#![allow(unused_imports, non_snake_case)]
#![allow(dead_code)]
use crate::{
    arraylist::List,
    ext::{iter::IterExtra, string::CharExtra},
    scanner::Scanner,
};
modint!();
fn main() {
    let mut scan = Scanner::new();
    let mut n = scan.chars();
    n.reverse();
    let mut z = Z::new(45);
    let mut w = Z::new((1..=n[0].sub_i64('0')).sumint());
    let mut x = Z::new(0);
    for i in 1..n.lens() {
        x += z;
        w = z * (1..n[i].sub_i64('0')).sumint().into() + w * n[i].sub_i64('0').into();
        z *= 45.into();
    }
    println!("{}", w + x);
}
pub mod ext {
    pub mod iter {
        use crate::{arraylist::List, independent::integer::Int};
        pub trait IterExtra: Iterator + Sized {
            fn list(self) -> List<Self::Item> {
                self.collect()
            }
            fn to<B: std::iter::FromIterator<Self::Item>>(self) -> B {
                self.collect()
            }
            fn counti(self) -> isize {
                self.count() as isize
            }
            fn enumeratei(
                self,
            ) -> std::iter::Map<
                std::iter::Enumerate<Self>,
                fn((usize, Self::Item)) -> (isize, Self::Item),
            > {
                self.enumerate().map(|t| (t.0 as isize, t.1))
            }
            fn sumint(self) -> Self::Item
            where
                Self::Item: Int,
            {
                self.fold(Self::Item::zero(), |acc, x| acc + x)
            }
            fn min_exn(self) -> Self::Item
            where
                Self::Item: Ord,
            {
                self.min().unwrap()
            }
            fn max_exn(self) -> Self::Item
            where
                Self::Item: Ord,
            {
                self.max().unwrap()
            }
        }
        impl<T> IterExtra for T where T: Iterator {}
    }
    pub mod string {
        use crate::{arraylist::List, independent::integer::Int};
        pub trait StringExtra {
            fn to_chars(self) -> List<char>;
        }
        impl StringExtra for String {
            fn to_chars(self) -> List<char> {
                self.chars().collect()
            }
        }
        pub trait CharExtra {
            fn sub(self, b: char) -> isize;
            fn sub_i64(self, b: char) -> i64;
            #[doc = " [start, end]"]
            fn in_range(self, start: char, end: char) -> bool;
            fn add<T: Int>(self, d: T) -> char;
        }
        impl CharExtra for char {
            fn sub(self, b: char) -> isize {
                self as isize - b as isize
            }
            fn sub_i64(self, b: char) -> i64 {
                self as i64 - b as i64
            }
            fn in_range(self, start: char, end: char) -> bool {
                (start as u8..=end as u8).contains(&(self as u8))
            }
            fn add<T: Int>(self, d: T) -> char {
                (d.to_u8() + self as u8) as char
            }
        }
    }
    pub mod range {
        use crate::independent::integer::Int;
        use std::cmp::{max, min};
        use std::ops::{Bound, Range, RangeBounds};
        pub trait IntRangeBounds<U: Int>: RangeBounds<U> {
            fn lbopt(&self) -> Option<U> {
                match self.start_bound() {
                    Bound::Included(x) => Some(*x),
                    Bound::Excluded(x) => Some(*x + U::one()),
                    Bound::Unbounded => None,
                }
            }
            fn ubopt(&self) -> Option<U> {
                match self.end_bound() {
                    Bound::Included(x) => Some(*x + U::one()),
                    Bound::Excluded(x) => Some(*x),
                    Bound::Unbounded => None,
                }
            }
            #[doc = " inclusive"]
            fn lower_bound(&self, limit: U) -> U {
                self.lbopt().map_or(limit, |x| max(limit, x))
            }
            #[doc = " exclusive"]
            fn upper_bound(&self, limit: U) -> U {
                self.ubopt().map_or(limit, |x| min(limit, x))
            }
            fn to_harfopen(&self, lb: U, ub: U) -> Range<U> {
                self.lower_bound(lb)..self.upper_bound(ub)
            }
            fn within(&self, mut t: U) -> U {
                if let Some(x) = self.lbopt() {
                    if t < x {
                        t = x;
                    }
                }
                if let Some(x) = self.ubopt() {
                    if x <= t {
                        t = x - U::one();
                    }
                }
                t
            }
            fn width(&self) -> U {
                if self.empty() {
                    U::zero()
                } else {
                    self.ubopt().unwrap() - self.lbopt().unwrap()
                }
            }
            fn empty(&self) -> bool {
                self.lbopt().is_none()
                    || self.ubopt().is_none()
                    || !(self.lbopt().unwrap() < self.ubopt().unwrap())
            }
            fn contain_range(&self, inner: &Self) -> bool {
                (match (self.lbopt(), inner.lbopt()) {
                    (Some(a), Some(b)) => a <= b,
                    (None, _) => true,
                    (Some(_), None) => false,
                }) && (match (inner.ubopt(), self.ubopt()) {
                    (Some(a), Some(b)) => a <= b,
                    (_, None) => true,
                    (None, Some(_)) => false,
                })
            }
            fn separate_range(&self, other: &Self) -> bool {
                if let (Some(a), Some(b)) = (self.ubopt(), other.lbopt()) {
                    if a <= b {
                        return true;
                    }
                }
                if let (Some(a), Some(b)) = (other.ubopt(), self.lbopt()) {
                    if a <= b {
                        return true;
                    }
                }
                false
            }
            fn overlap(&self, other: &Self) -> Range<U> {
                let left = if let (Some(a), Some(b)) = (self.lbopt(), other.lbopt()) {
                    max(a, b)
                } else {
                    self.lbopt().or(other.lbopt()).unwrap()
                };
                let right = if let (Some(a), Some(b)) = (self.ubopt(), other.ubopt()) {
                    min(a, b)
                } else {
                    self.ubopt().or(other.ubopt()).unwrap()
                };
                left..right
            }
        }
        impl<T: ?Sized, U: Int> IntRangeBounds<U> for T where T: RangeBounds<U> {}
    }
}
pub mod arraylist {
    use crate::{ext::range::IntRangeBounds, independent::integer::Int};
    use std::fmt::Formatter;
    use std::iter::FromIterator;
    use std::ops::{Index, IndexMut, RangeBounds};
    use std::slice::Iter;
    #[derive(Clone, PartialEq, Eq)]
    pub struct List<T> {
        pub vec: Vec<T>,
    }
    impl<T> List<T> {
        #[inline]
        pub fn new() -> List<T> {
            List { vec: vec![] }
        }
        #[inline]
        pub fn init(init: T, n: isize) -> List<T>
        where
            T: Clone,
        {
            List {
                vec: vec![init; n as usize],
            }
        }
        #[inline]
        pub fn from_vec(vec: Vec<T>) -> List<T> {
            List { vec }
        }
        #[inline]
        pub fn acc<'a, S>(n: isize, mut f: S) -> List<T>
        where
            S: FnMut(isize) -> T + 'a,
        {
            (0..n).map(|i| f(i)).collect()
        }
        #[inline]
        pub fn lens(&self) -> isize {
            self.vec.len() as isize
        }
        #[inline]
        pub fn iter(&self) -> Iter<'_, T> {
            self.vec.iter()
        }
        #[inline]
        pub fn push(&mut self, item: T) {
            self.vec.push(item);
        }
        #[inline]
        pub fn sort(&mut self)
        where
            T: Ord,
        {
            self.vec.sort();
        }
        #[inline]
        pub fn reverse(&mut self) {
            self.vec.reverse();
        }
        #[inline]
        pub fn sort_by<F>(&mut self, compare: F)
        where
            F: FnMut(&T, &T) -> std::cmp::Ordering,
        {
            self.vec.sort_by(compare)
        }
        #[inline]
        pub fn sort_by_key<K, F>(&mut self, compare: F)
        where
            F: FnMut(&T) -> K,
            K: Ord,
        {
            self.vec.sort_by_key(compare)
        }
        #[inline]
        pub fn first(&self) -> Option<&T> {
            self.vec.first()
        }
        #[inline]
        pub fn last(&self) -> Option<&T> {
            self.vec.last()
        }
        #[inline]
        pub fn pop(&mut self) -> Option<T> {
            self.vec.pop()
        }
        #[inline]
        pub fn swap(&mut self, i: isize, j: isize) {
            self.vec.swap(i as usize, j as usize);
        }
        #[inline]
        pub fn append(&mut self, mut other: Self) {
            self.vec.append(&mut other.vec);
        }
        #[inline]
        pub fn extend(&mut self, other: impl Iterator<Item = T>) {
            self.vec.extend(other);
        }
        #[inline]
        pub fn mrr(&self) -> std::iter::Cloned<Iter<T>>
        where
            T: Clone,
        {
            self.iter().cloned()
        }
        #[inline]
        pub fn join(&self, sep: &str) -> String
        where
            T: std::fmt::Display,
        {
            self.iter()
                .map(|x| format!("{}", x))
                .collect::<Vec<_>>()
                .join(sep)
        }
        #[inline]
        pub fn map<B, F>(&self, f: F) -> List<B>
        where
            T: Clone,
            F: FnMut(T) -> B,
        {
            self.mrr().map(f).collect()
        }
        #[inline]
        pub fn filter<P>(&self, predicate: P) -> List<T>
        where
            T: Clone,
            P: FnMut(&T) -> bool,
        {
            self.mrr().filter(predicate).collect()
        }
        #[inline]
        pub fn filter_map<B, F>(&self, f: F) -> List<B>
        where
            T: Clone,
            F: FnMut(T) -> Option<B>,
        {
            self.mrr().filter_map(f).collect()
        }
        #[doc = " |acc, x| -> acc"]
        #[inline]
        pub fn fold<B, F>(&self, init: B, f: F) -> B
        where
            T: Clone,
            F: FnMut(B, T) -> B,
        {
            self.mrr().fold(init, f)
        }
        #[inline]
        pub fn any<P>(&self, predicate: P) -> bool
        where
            P: FnMut(&T) -> bool,
        {
            self.iter().any(predicate)
        }
        #[inline]
        pub fn all<P>(&self, predicate: P) -> bool
        where
            P: FnMut(&T) -> bool,
        {
            self.iter().all(predicate)
        }
        #[inline]
        pub fn sum(&self) -> T
        where
            T: Int,
        {
            self.iter().cloned().fold(T::zero(), |acc, x| acc + x)
        }
        #[inline]
        pub fn enumerate(&self) -> List<(isize, T)>
        where
            T: Clone,
        {
            self.mrr()
                .enumerate()
                .map(|p| (p.0 as isize, p.1))
                .collect()
        }
        #[inline]
        pub fn find<P>(&self, mut predicate: P) -> Option<&T>
        where
            P: FnMut(&T) -> bool,
        {
            self.iter().find(|x| predicate(*x))
        }
        #[inline]
        pub fn index_of<P>(&self, mut predicate: P) -> Option<isize>
        where
            P: FnMut(&T) -> bool,
        {
            self.iter()
                .enumerate()
                .find(|&(_i, x)| predicate(x))
                .map(|p| p.0 as isize)
        }
        #[inline]
        pub fn to<B: FromIterator<T>>(&self) -> B
        where
            T: Clone,
        {
            self.mrr().collect()
        }
        #[inline]
        pub fn min(&self) -> Option<&T>
        where
            T: Ord,
        {
            self.iter().min()
        }
        #[inline]
        pub fn max(&self) -> Option<&T>
        where
            T: Ord,
        {
            self.iter().max()
        }
        #[inline]
        pub fn argmin(&self) -> Option<isize>
        where
            T: Ord,
        {
            let item = self.iter().min()?;
            self.iter()
                .enumerate()
                .find(|p| p.1 == item)
                .map(|p| p.0 as isize)
        }
        #[inline]
        pub fn argmax(&self) -> Option<isize>
        where
            T: Ord,
        {
            let item = self.iter().max()?;
            self.iter()
                .enumerate()
                .find(|p| p.1 == item)
                .map(|p| p.0 as isize)
        }
        #[inline]
        pub fn part<U>(&self, range: U) -> List<T>
        where
            T: Clone,
            U: RangeBounds<isize>,
        {
            List::from_vec(
                self.vec[range.lower_bound(0) as usize..range.upper_bound(self.lens()) as usize]
                    .to_vec(),
            )
        }
        #[inline]
        pub fn first_exn(&self) -> &T {
            self.first().unwrap()
        }
        #[inline]
        pub fn last_exn(&self) -> &T {
            self.last().unwrap()
        }
        #[inline]
        pub fn pop_exn(&mut self) -> T {
            self.pop().unwrap()
        }
        #[inline]
        pub fn min_exn(&self) -> &T
        where
            T: Ord,
        {
            self.min().unwrap()
        }
        #[inline]
        pub fn max_exn(&self) -> &T
        where
            T: Ord,
        {
            self.max().unwrap()
        }
        #[inline]
        pub fn argmin_exn(&self) -> isize
        where
            T: Ord,
        {
            self.argmin().unwrap()
        }
        #[inline]
        pub fn argmax_exn(&self) -> isize
        where
            T: Ord,
        {
            self.argmax().unwrap()
        }
        #[inline]
        pub fn find_exn<P>(&self, predicate: P) -> &T
        where
            P: FnMut(&T) -> bool,
        {
            self.find(predicate).unwrap()
        }
        #[inline]
        pub fn index_of_exn<P>(&self, predicate: P) -> isize
        where
            P: FnMut(&T) -> bool,
        {
            self.index_of(predicate).unwrap()
        }
    }
    impl<T> std::ops::BitXorAssign<T> for List<T> {
        #[inline]
        fn bitxor_assign(&mut self, rhs: T) {
            self.push(rhs);
        }
    }
    impl<T> Index<isize> for List<T> {
        type Output = T;
        #[inline]
        fn index(&self, index: isize) -> &Self::Output {
            if cfg!(debug_assertions) {
                self.vec.index(index as usize)
            } else {
                unsafe { self.vec.get_unchecked(index as usize) }
            }
        }
    }
    impl<T> IndexMut<isize> for List<T> {
        #[inline]
        fn index_mut(&mut self, index: isize) -> &mut Self::Output {
            if cfg!(debug_assertions) {
                self.vec.index_mut(index as usize)
            } else {
                unsafe { self.vec.get_unchecked_mut(index as usize) }
            }
        }
    }
    impl<T> FromIterator<T> for List<T> {
        fn from_iter<U: IntoIterator<Item = T>>(iter: U) -> Self {
            List {
                vec: iter.into_iter().collect(),
            }
        }
    }
    impl<T> IntoIterator for List<T> {
        type Item = T;
        type IntoIter = std::vec::IntoIter<T>;
        fn into_iter(self) -> std::vec::IntoIter<T> {
            self.vec.into_iter()
        }
    }
    impl<'a, T> IntoIterator for &'a List<T> {
        type Item = &'a T;
        type IntoIter = Iter<'a, T>;
        fn into_iter(self) -> Iter<'a, T> {
            self.vec.iter()
        }
    }
    impl<T: std::fmt::Display> std::fmt::Display for List<T> {
        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
            write!(
                f,
                "{}",
                self.iter()
                    .map(|x| format!("{}", x))
                    .collect::<Vec<_>>()
                    .join(" ")
            )
        }
    }
    impl<T: std::fmt::Debug> std::fmt::Debug for List<T> {
        fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
            write!(
                f,
                "[{}]",
                self.iter()
                    .map(|x| format!("{:?}", x))
                    .collect::<Vec<_>>()
                    .join(", ")
            )
        }
    }
    impl<T> From<Vec<T>> for List<T> {
        fn from(vec: Vec<T>) -> Self {
            Self::from_vec(vec)
        }
    }
    impl<T: Clone> From<&[T]> for List<T> {
        fn from(slice: &[T]) -> Self {
            slice.iter().cloned().collect()
        }
    }
    #[macro_export]
    macro_rules ! list { () => { $ crate :: arraylist :: List :: new () } ; ($ ($ v : expr) ,+ $ (,) ?) => { $ crate :: arraylist :: List :: from_vec ([$ ($ v) ,+] . to_vec ()) } ; ($ v : expr ; $ a : expr) => { $ crate :: arraylist :: List :: init ($ v , $ a) } ; ($ v : expr ; $ a : expr ; $ ($ rest : expr) ;+) => { $ crate :: arraylist :: List :: init (list ! ($ v ; $ ($ rest) ;+) , $ a) } ; }
}
pub mod independent {
    pub mod integer {
        use std::fmt::Display;
        pub trait Int:
            std::ops::Add<Output = Self>
            + std::ops::Sub<Output = Self>
            + std::ops::Mul<Output = Self>
            + std::ops::Div<Output = Self>
            + std::ops::Rem<Output = Self>
            + std::ops::AddAssign
            + std::ops::SubAssign
            + std::ops::MulAssign
            + std::ops::DivAssign
            + std::hash::Hash
            + PartialEq
            + Eq
            + PartialOrd
            + Ord
            + Copy
            + Display
        {
            fn to_u8(&self) -> u8;
            fn to_u16(&self) -> u16;
            fn to_u32(&self) -> u32;
            fn to_u64(&self) -> u64;
            fn to_u128(&self) -> u128;
            fn to_i8(&self) -> i8;
            fn to_i16(&self) -> i16;
            fn to_i32(&self) -> i32;
            fn to_i64(&self) -> i64;
            fn to_i128(&self) -> i128;
            fn to_usize(&self) -> usize;
            fn to_isize(&self) -> isize;
            fn from_u8(x: u8) -> Self;
            fn from_u16(x: u16) -> Self;
            fn from_u32(x: u32) -> Self;
            fn from_u64(x: u64) -> Self;
            fn from_u128(x: u128) -> Self;
            fn from_i8(x: i8) -> Self;
            fn from_i16(x: i16) -> Self;
            fn from_i32(x: i32) -> Self;
            fn from_i64(x: i64) -> Self;
            fn from_i128(x: i128) -> Self;
            fn from_usize(x: usize) -> Self;
            fn from_isize(x: isize) -> Self;
            fn zero() -> Self;
            fn one() -> Self;
            fn next(&self) -> Self {
                *self + Self::one()
            }
        }
        macro_rules ! impl_integer_functions { ($ selftpe : ident , $ ($ tofn : ident , $ fromfn : ident , $ tpe : ident) ,*) => { $ (fn $ tofn (& self) -> $ tpe { * self as $ tpe } fn $ fromfn (x : $ tpe) -> Self { x as $ selftpe }) * } ; }
        macro_rules ! impl_integer { ($ ($ tpe : ident) ,*) => { $ (impl Int for $ tpe { impl_integer_functions ! ($ tpe , to_u8 , from_u8 , u8 , to_u16 , from_u16 , u16 , to_u32 , from_u32 , u32 , to_u64 , from_u64 , u64 , to_u128 , from_u128 , u128 , to_i8 , from_i8 , i8 , to_i16 , from_i16 , i16 , to_i32 , from_i32 , i32 , to_i64 , from_i64 , i64 , to_i128 , from_i128 , i128 , to_usize , from_usize , usize , to_isize , from_isize , isize) ; fn zero () -> Self { 0 } fn one () -> Self { 1 } }) * } ; }
        impl_integer!(u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, usize, isize);
    }
}
pub mod modulo {
    use crate::independent::integer::Int;
    use std::marker::PhantomData;
    use std::ops::*;
    #[derive(Debug, PartialEq, Eq, Copy, Clone, Hash, PartialOrd, Ord)]
    pub struct ModInt<T>(pub i64, PhantomData<*const T>);
    impl<T: ConstValue> ModInt<T> {
        pub fn new<U: Int>(a: U) -> ModInt<T> {
            let x = a.to_i64();
            if x < 0 {
                ModInt::raw(x % T::M + T::M)
            } else if x < T::M {
                ModInt::raw(x)
            } else {
                ModInt::raw(x % T::M)
            }
        }
        pub fn pow<U: Int>(self, x: U) -> Self {
            let mut n = x.to_i64();
            let mut a = self;
            let mut res = Self::raw(1);
            while n > 0 {
                if n & 1 == 1 {
                    res *= a;
                }
                a = a * a;
                n >>= 1;
            }
            res
        }
        pub fn inv(self) -> Self {
            self.pow(T::M - 2)
        }
        #[inline]
        fn raw(x: i64) -> ModInt<T> {
            ModInt(x, PhantomData)
        }
    }
    pub trait ConstValue: PartialEq + Eq + Copy + Clone + std::hash::Hash + Ord {
        const M: i64;
    }
    impl<T> std::fmt::Display for ModInt<T> {
        fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
            write!(f, "{}", self.0)
        }
    }
    macro_rules ! impl_from_for_modint { ($ ($ tpe : ident) ,*) => { $ (impl < T : ConstValue > From <$ tpe > for ModInt < T > { fn from (n : $ tpe) -> Self { Self :: new (n) } }) * } ; }
    impl_from_for_modint!(u8, u16, u32, u64, u128, i8, i16, i32, i64, i128, usize, isize);
    impl<T: ConstValue> Add for ModInt<T> {
        type Output = ModInt<T>;
        fn add(self, other: ModInt<T>) -> ModInt<T> {
            let mut ret = self.0 + other.0;
            if ret >= T::M {
                ret -= T::M;
            }
            Self::raw(ret)
        }
    }
    impl<T: ConstValue> Sub for ModInt<T> {
        type Output = ModInt<T>;
        fn sub(self, other: ModInt<T>) -> ModInt<T> {
            let mut ret = self.0 + T::M - other.0;
            if ret >= T::M {
                ret -= T::M
            }
            Self::raw(ret)
        }
    }
    impl<T: ConstValue> Mul for ModInt<T> {
        type Output = ModInt<T>;
        fn mul(self, other: ModInt<T>) -> ModInt<T> {
            Self::raw(self.0 * other.0 % T::M)
        }
    }
    impl<T: ConstValue> Div for ModInt<T> {
        type Output = ModInt<T>;
        fn div(self, other: ModInt<T>) -> ModInt<T> {
            self * other.inv()
        }
    }
    impl<T: ConstValue> Rem for ModInt<T> {
        type Output = ModInt<T>;
        fn rem(self, other: ModInt<T>) -> ModInt<T> {
            Self::raw(self.0 % other.0)
        }
    }
    macro_rules! impl_assign {
        ($ t : ty , $ f : ident , $ f2 : ident) => {
            impl<T: ConstValue> $t for ModInt<T> {
                fn $f(&mut self, other: Self) {
                    *self = self.$f2(other);
                }
            }
        };
    }
    impl_assign!(AddAssign, add_assign, add);
    impl_assign!(SubAssign, sub_assign, sub);
    impl_assign!(MulAssign, mul_assign, mul);
    impl_assign!(DivAssign, div_assign, div);
    impl_assign!(RemAssign, rem_assign, rem);
    #[macro_export]
    macro_rules! modint {
        () => {
            modint!(1000000007);
        };
        ($ m : expr) => {
            #[derive(Debug, PartialEq, Eq, Copy, Clone, Hash, PartialOrd, Ord)]
            pub enum __M {}
            impl $crate::modulo::ConstValue for __M {
                const M: i64 = $m;
            }
            #[allow(dead_code)]
            type Z = $crate::modulo::ModInt<__M>;
        };
    }
    macro_rules ! impl_integer_functions { ($ ($ tofn : ident , $ fromfn : ident , $ tpe : ident) ,*) => { $ (fn $ tofn (& self) -> $ tpe { self . 0 as $ tpe } fn $ fromfn (x : $ tpe) -> Self { Self :: new (x) }) * } ; }
    impl<T: ConstValue> Int for ModInt<T> {
        impl_integer_functions!(
            to_u8, from_u8, u8, to_u16, from_u16, u16, to_u32, from_u32, u32, to_u64, from_u64,
            u64, to_u128, from_u128, u128, to_i8, from_i8, i8, to_i16, from_i16, i16, to_i32,
            from_i32, i32, to_i64, from_i64, i64, to_i128, from_i128, i128, to_usize, from_usize,
            usize, to_isize, from_isize, isize
        );
        fn zero() -> Self {
            Self::new(0)
        }
        fn one() -> Self {
            Self::new(1)
        }
    }
}
pub mod scanner {
    use crate::arraylist::List;
    use std::io::{stdin, BufReader, Bytes, Read, Stdin};
    use std::str::FromStr;
    pub struct Scanner {
        buf: Bytes<BufReader<Stdin>>,
    }
    impl Scanner {
        pub fn new() -> Scanner {
            Scanner {
                buf: BufReader::new(stdin()).bytes(),
            }
        }
        pub fn read_next<T: FromStr>(&mut self) -> Option<T> {
            let token = self
                .buf
                .by_ref()
                .map(|c| c.unwrap() as char)
                .skip_while(|c| c.is_whitespace())
                .take_while(|c| !c.is_whitespace())
                .collect::<String>();
            token.parse::<T>().ok()
        }
        pub fn read<T: FromStr>(&mut self) -> T {
            self.read_next().unwrap()
        }
        pub fn readn<T: FromStr>(&mut self, n: isize) -> List<T> {
            (0..n).map(|_| self.read::<T>()).collect()
        }
        pub fn chars(&mut self) -> List<char> {
            self.read::<String>().chars().collect()
        }
    }
}