fn main() { let (a, m) = read(); let n = a.len(); let pc = precalc::Precalc::new(n + 2); let mut f = vec![M::zero(); n + 1]; for (i, f) in f.iter_mut().enumerate() { *f = pc.ifact(i + 1); } let mut bernoulli = f.inverse(n + 1); bernoulli[1] = -bernoulli[1]; let prefix_sum = |mut a: Vec| -> Vec { let z = std::mem::replace(&mut a[0], M::zero()); let n = a.len(); for (i, a) in a.iter_mut().enumerate() { *a *= pc.fact(i); } a.reverse(); a = a.multiply(&bernoulli[..n]); a.truncate(n); a.push(M::zero()); a.reverse(); for (i, a) in a.iter_mut().enumerate() { *a *= pc.ifact(i); } a[0] += z; a[1] += z; a }; let taylor_shift = |a: Vec, c: M| -> Vec { let mut b = a.clone(); for (i, b) in b.iter_mut().enumerate() { *b *= pc.fact(i); } b.reverse(); let mut d = vec![M::one(); a.len()]; for i in 1..a.len() { d[i] = d[i - 1] * c * pc.inv(i); } let mut res = b.multiply(&d); res.truncate(a.len()); res.reverse(); for (i, res) in res.iter_mut().enumerate() { *res *= pc.ifact(i); } res }; let mut m = m .into_iter() .map(|c| (c - b'0') as usize) .collect::>(); let mut dp = vec![M::one()]; for &q in a[1..].iter() { let rem = div_rem(&mut m, q); dp = taylor_shift(dp, M::from(rem)); for (i, dp) in dp.iter_mut().enumerate() { *dp *= M::from(q).pow(i as u64); } dp = prefix_sum(dp); } let rem = div_rem(&mut m, 998_244_353); let ans = dp.eval(M::from(rem)); println!("{}", ans); } pub fn div_rem(m: &mut [usize], d: usize) -> usize { let mut rem = 0; for m in m.iter_mut() { let v = 10 * rem + *m; *m = v / d; rem = v % d; } rem } fn read() -> (Vec, Vec) { use std::io::*; let mut s = String::new(); std::io::stdin().read_to_string(&mut s).unwrap(); let mut it = s.trim().split_whitespace(); let n = it.next().unwrap().parse::().unwrap(); let a = (0..n) .map(|_| it.next().unwrap().parse::().unwrap()) .collect::>(); let m = it.next().unwrap().bytes().collect(); (a, m) } // ---------- begin ModInt ---------- mod modint { use std::marker::*; use std::ops::*; pub trait Modulo { fn modulo() -> u32; fn rem() -> u32; fn ini() -> u64; fn reduce(x: u64) -> u32 { debug_assert!(x < (Self::modulo() as u64) << 32); let b = (x as u32 * Self::rem()) as u64; let t = x + b * Self::modulo() as u64; let mut c = (t >> 32) as u32; if c >= Self::modulo() { c -= Self::modulo(); } c as u32 } } #[allow(dead_code)] pub enum Mod998_244_353 {} impl Modulo for Mod998_244_353 { fn modulo() -> u32 { 998_244_353 } fn rem() -> u32 { 998244351 } fn ini() -> u64 { 932051910 } } pub struct ModInt(u32, PhantomData); impl Clone for ModInt { fn clone(&self) -> Self { ModInt::build(self.0) } } impl Copy for ModInt {} impl Add for ModInt { type Output = ModInt; fn add(self, rhs: Self) -> Self::Output { let mut d = self.0 + rhs.0; if d >= T::modulo() { d -= T::modulo(); } Self::build(d) } } impl AddAssign for ModInt { fn add_assign(&mut self, rhs: Self) { *self = *self + rhs; } } impl Sub for ModInt { type Output = ModInt; fn sub(self, rhs: Self) -> Self::Output { let mut d = self.0 - rhs.0; if self.0 < rhs.0 { d += T::modulo(); } Self::build(d) } } impl SubAssign for ModInt { fn sub_assign(&mut self, rhs: Self) { *self = *self - rhs; } } impl Mul for ModInt { type Output = ModInt; fn mul(self, rhs: Self) -> Self::Output { Self::build(T::reduce(self.0 as u64 * rhs.0 as u64)) } } impl MulAssign for ModInt { fn mul_assign(&mut self, rhs: Self) { *self = *self * rhs; } } impl Neg for ModInt { type Output = ModInt; fn neg(self) -> Self::Output { if self.0 == 0 { Self::zero() } else { Self::build(T::modulo() - self.0) } } } impl std::fmt::Display for ModInt { fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result { write!(f, "{}", self.get()) } } impl std::fmt::Debug for ModInt { fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result { write!(f, "{}", self.get()) } } impl std::str::FromStr for ModInt { type Err = std::num::ParseIntError; fn from_str(s: &str) -> Result { let val = s.parse::()?; Ok(ModInt::new(val)) } } impl From for ModInt { fn from(val: usize) -> ModInt { ModInt::new_unchecked((val % T::modulo() as usize) as u32) } } impl From for ModInt { fn from(val: u64) -> ModInt { ModInt::new_unchecked((val % T::modulo() as u64) as u32) } } impl From for ModInt { fn from(val: i64) -> ModInt { let m = T::modulo() as i64; ModInt::new((val % m + m) as u32) } } #[allow(dead_code)] impl ModInt { fn build(d: u32) -> Self { ModInt(d, PhantomData) } pub fn zero() -> Self { Self::build(0) } pub fn is_zero(&self) -> bool { self.0 == 0 } } #[allow(dead_code)] impl ModInt { pub fn new_unchecked(d: u32) -> Self { Self::build(T::reduce(d as u64 * T::ini())) } pub fn new(d: u32) -> Self { Self::new_unchecked(d % T::modulo()) } pub fn one() -> Self { Self::new_unchecked(1) } pub fn get(&self) -> u32 { T::reduce(self.0 as u64) } pub fn pow(&self, mut n: u64) -> Self { let mut t = Self::one(); let mut s = *self; while n > 0 { if n & 1 == 1 { t *= s; } s *= s; n >>= 1; } t } pub fn inv(&self) -> Self { assert!(!self.is_zero()); self.pow((T::modulo() - 2) as u64) } pub fn binom(n: usize, k: usize) -> Self { if n < k { return Self::zero(); } let k = k.min(n - k); let mut nu = Self::one(); let mut de = Self::one(); for i in 0..k { nu *= Self::from(n - i); de *= Self::from(i + 1); } nu * de.inv() } } } // ---------- end ModInt ---------- // ---------- begin Precalc ---------- mod precalc { use super::modint::*; #[allow(dead_code)] pub struct Precalc { inv: Vec>, fact: Vec>, ifact: Vec>, } #[allow(dead_code)] impl Precalc { pub fn new(n: usize) -> Precalc { let mut inv = vec![ModInt::one(); n + 1]; let mut fact = vec![ModInt::one(); n + 1]; let mut ifact = vec![ModInt::one(); n + 1]; for i in 2..(n + 1) { fact[i] = fact[i - 1] * ModInt::new_unchecked(i as u32); } ifact[n] = fact[n].inv(); if n > 0 { inv[n] = ifact[n] * fact[n - 1]; } for i in (1..n).rev() { ifact[i] = ifact[i + 1] * ModInt::new_unchecked((i + 1) as u32); inv[i] = ifact[i] * fact[i - 1]; } Precalc { inv: inv, fact: fact, ifact: ifact, } } pub fn inv(&self, n: usize) -> ModInt { assert!(n > 0); self.inv[n] } pub fn fact(&self, n: usize) -> ModInt { self.fact[n] } pub fn ifact(&self, n: usize) -> ModInt { self.ifact[n] } pub fn perm(&self, n: usize, k: usize) -> ModInt { if k > n { return ModInt::zero(); } self.fact[n] * self.ifact[n - k] } pub fn binom(&self, n: usize, k: usize) -> ModInt { if k > n { return ModInt::zero(); } self.fact[n] * self.ifact[k] * self.ifact[n - k] } } } // ---------- end Precalc ---------- use modint::*; pub trait NTTFriendly: modint::Modulo { fn order() -> usize; fn zeta() -> u32; } type M = ModInt; impl NTTFriendly for Mod998_244_353 { fn order() -> usize { 8388608 } fn zeta() -> u32 { 15311432 } } use std::ops::*; pub trait Zero: Sized + Add { fn zero() -> Self; } pub fn zero() -> T { T::zero() } impl Zero for ModInt { fn zero() -> Self { Self::zero() } } impl Zero for usize { fn zero() -> Self { 0 } } pub trait ArrayAdd { type Item; fn add(&self, rhs: &[Self::Item]) -> Vec; } impl ArrayAdd for [T] where T: Zero + Copy, { type Item = T; fn add(&self, rhs: &[Self::Item]) -> Vec { let mut c = vec![T::zero(); self.len().max(rhs.len())]; c[..self.len()].copy_from_slice(self); c.add_assign(rhs); c } } pub trait ArrayAddAssign { type Item; fn add_assign(&mut self, rhs: &[Self::Item]); } impl ArrayAddAssign for [T] where T: Add + Copy, { type Item = T; fn add_assign(&mut self, rhs: &[Self::Item]) { assert!(self.len() >= rhs.len()); self.iter_mut().zip(rhs).for_each(|(x, a)| *x = *x + *a); } } impl ArrayAddAssign for Vec where T: Zero + Add + Copy, { type Item = T; fn add_assign(&mut self, rhs: &[Self::Item]) { if self.len() < rhs.len() { self.resize(rhs.len(), T::zero()); } self.as_mut_slice().add_assign(rhs); } } pub trait ArraySub { type Item; fn sub(&self, rhs: &[Self::Item]) -> Vec; } impl ArraySub for [T] where T: Zero + Sub + Copy, { type Item = T; fn sub(&self, rhs: &[Self::Item]) -> Vec { let mut c = vec![T::zero(); self.len().max(rhs.len())]; c[..self.len()].copy_from_slice(self); c.sub_assign(rhs); c } } pub trait ArraySubAssign { type Item; fn sub_assign(&mut self, rhs: &[Self::Item]); } impl ArraySubAssign for [T] where T: Sub + Copy, { type Item = T; fn sub_assign(&mut self, rhs: &[Self::Item]) { assert!(self.len() >= rhs.len()); self.iter_mut().zip(rhs).for_each(|(x, a)| *x = *x - *a); } } impl ArraySubAssign for Vec where T: Zero + Sub + Copy, { type Item = T; fn sub_assign(&mut self, rhs: &[Self::Item]) { if self.len() < rhs.len() { self.resize(rhs.len(), T::zero()); } self.as_mut_slice().sub_assign(rhs); } } pub trait ArrayDot { type Item; fn dot(&self, rhs: &[Self::Item]) -> Vec; } impl ArrayDot for [T] where T: Mul + Copy, { type Item = T; fn dot(&self, rhs: &[Self::Item]) -> Vec { assert!(self.len() == rhs.len()); self.iter().zip(rhs).map(|p| *p.0 * *p.1).collect() } } pub trait ArrayDotAssign { type Item; fn dot_assign(&mut self, rhs: &[Self::Item]); } impl ArrayDotAssign for [T] where T: MulAssign + Copy, { type Item = T; fn dot_assign(&mut self, rhs: &[Self::Item]) { assert!(self.len() == rhs.len()); self.iter_mut().zip(rhs).for_each(|(x, a)| *x *= *a); } } pub trait ArrayMul { type Item; fn mul(&self, rhs: &[Self::Item]) -> Vec; } impl ArrayMul for [T] where T: Zero + Mul + Copy, { type Item = T; fn mul(&self, rhs: &[Self::Item]) -> Vec { if self.is_empty() || rhs.is_empty() { return vec![]; } let mut res = vec![zero(); self.len() + rhs.len() - 1]; for (i, a) in self.iter().enumerate() { for (c, b) in res[i..].iter_mut().zip(rhs) { *c = *c + *a * *b; } } res } } pub trait ArrayNTT { type Item; fn ntt(&mut self); fn intt(&mut self); fn multiply(&self, rhs: &[Self::Item]) -> Vec; } impl ArrayNTT for [ModInt] where T: NTTFriendly, { type Item = ModInt; fn ntt(&mut self) { let f = self; let n = f.len(); assert!(n.count_ones() == 1); assert!(n <= T::order()); let len = n.trailing_zeros() as usize; let mut es = [ModInt::zero(); 30]; let mut ies = [ModInt::zero(); 30]; let mut sum_e = [ModInt::zero(); 30]; let cnt2 = T::order().trailing_zeros() as usize; let mut e = ModInt::new_unchecked(T::zeta()); let mut ie = e.inv(); for i in (2..=cnt2).rev() { es[i - 2] = e; ies[i - 2] = ie; e = e * e; ie = ie * ie; } let mut now = ModInt::one(); for i in 0..(cnt2 - 1) { sum_e[i] = es[i] * now; now *= ies[i]; } for ph in 1..=len { let p = 1 << (len - ph); let mut now = ModInt::one(); for (i, f) in f.chunks_exact_mut(2 * p).enumerate() { let (x, y) = f.split_at_mut(p); for (x, y) in x.iter_mut().zip(y.iter_mut()) { let l = *x; let r = *y * now; *x = l + r; *y = l - r; } now *= sum_e[(!i).trailing_zeros() as usize]; } } } fn intt(&mut self) { let f = self; let n = f.len(); assert!(n.count_ones() == 1); assert!(n <= T::order()); let len = n.trailing_zeros() as usize; let mut es = [ModInt::zero(); 30]; let mut ies = [ModInt::zero(); 30]; let mut sum_ie = [ModInt::zero(); 30]; let cnt2 = T::order().trailing_zeros() as usize; let mut e = ModInt::new_unchecked(T::zeta()); let mut ie = e.inv(); for i in (2..=cnt2).rev() { es[i - 2] = e; ies[i - 2] = ie; e = e * e; ie = ie * ie; } let mut now = ModInt::one(); for i in 0..(cnt2 - 1) { sum_ie[i] = ies[i] * now; now *= es[i]; } for ph in (1..=len).rev() { let p = 1 << (len - ph); let mut inow = ModInt::one(); for (i, f) in f.chunks_exact_mut(2 * p).enumerate() { let (x, y) = f.split_at_mut(p); for (x, y) in x.iter_mut().zip(y.iter_mut()) { let l = *x; let r = *y; *x = l + r; *y = (l - r) * inow; } inow *= sum_ie[(!i).trailing_zeros() as usize]; } } let ik = ModInt::new_unchecked((T::modulo() + 1) >> 1).pow(len as u64); for f in f.iter_mut() { *f *= ik; } } fn multiply(&self, rhs: &[Self::Item]) -> Vec { if self.len().min(rhs.len()) <= 32 { return self.mul(rhs); } let size = (self.len() + rhs.len() - 1).next_power_of_two(); let mut f = vec![ModInt::zero(); size]; let mut g = vec![ModInt::zero(); size]; f[..self.len()].copy_from_slice(self); g[..rhs.len()].copy_from_slice(rhs); f.ntt(); g.ntt(); f.dot_assign(&g); f.intt(); f.truncate(self.len() + rhs.len() - 1); f } } pub trait PolynomialOperation { type Item; fn eval(&self, x: Self::Item) -> Self::Item; fn derivative(&self) -> Vec; fn integral(&self) -> Vec; } impl PolynomialOperation for [ModInt] { type Item = ModInt; fn eval(&self, x: Self::Item) -> Self::Item { self.iter().rev().fold(ModInt::zero(), |s, a| s * x + *a) } fn derivative(&self) -> Vec { if self.len() <= 1 { return vec![]; } self[1..] .iter() .enumerate() .map(|(k, a)| ModInt::new_unchecked(k as u32 + 1) * *a) .collect() } fn integral(&self) -> Vec { if self.is_empty() { return vec![]; } let mut inv = vec![ModInt::one(); self.len() + 1]; let mut mul = ModInt::zero(); for i in 1..=self.len() { mul += ModInt::one(); inv[i] = inv[i - 1] * mul; } let mut prod = inv[self.len()].inv(); for i in (1..=self.len()).rev() { inv[i] = self[i - 1] * inv[i - 1] * prod; prod *= mul; mul -= ModInt::one(); } inv[0] = ModInt::zero(); inv } } pub trait FPSOperation { type Item; fn inverse(&self, n: usize) -> Vec; fn log(&self, n: usize) -> Vec; fn exp(&self, n: usize) -> Vec; } impl FPSOperation for [ModInt] { type Item = ModInt; fn inverse(&self, n: usize) -> Vec { assert!(self.len() > 0 && !self[0].is_zero()); let len = n.next_power_of_two(); assert!(2 * len <= T::order()); let mut b = vec![ModInt::zero(); n]; b[0] = self[0].inv(); let mut f = Vec::with_capacity(2 * len); let mut g = Vec::with_capacity(2 * len); let mut size = 1; while size < n { g.clear(); g.extend(b.iter().take(size)); g.resize(2 * size, ModInt::zero()); f.clear(); f.extend(self.iter().take(2 * size)); f.resize(2 * size, ModInt::zero()); f.ntt(); g.ntt(); f.dot_assign(&g); f.intt(); f[..size].iter_mut().for_each(|f| *f = ModInt::zero()); f.ntt(); f.dot_assign(&g); f.intt(); for (b, g) in b[size..].iter_mut().zip(&f[size..]) { *b = *b - *g; } size *= 2; } b } fn log(&self, n: usize) -> Vec { assert!(self.get(0).map_or(false, |p| p.get() == 1)); let mut b = self.derivative().multiply(&self.inverse(n)); b.truncate(n - 1); let mut b = b.integral(); b.resize(n, ModInt::zero()); b } fn exp(&self, n: usize) -> Vec { assert!(self.get(0).map_or(true, |a| a.is_zero())); assert!(n <= T::order()); let mut b = vec![ModInt::one()]; let mut size = 1; while size < n { size <<= 1; let f = b.log(size); let g = self[..self.len().min(size)].sub(&f); b = b.multiply(&g).add(&b); b.truncate(size); } b.truncate(n); b.resize(n, ModInt::zero()); b } } // test // yuki907: https://yukicoder.me/submissions/712523 // hhkb2020: https://atcoder.jp/contests/hhkb2020/submissions/26997806 //