#[allow(unused_imports)] use std::cmp::*; // https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8 macro_rules! input { ($($r:tt)*) => { let stdin = std::io::stdin(); let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock())); let mut next = move || -> String{ bytes.by_ref().map(|r|r.unwrap() as char) .skip_while(|c|c.is_whitespace()) .take_while(|c|!c.is_whitespace()) .collect() }; input_inner!{next, $($r)*} }; } macro_rules! input_inner { ($next:expr) => {}; ($next:expr,) => {}; ($next:expr, $var:ident : $t:tt $($r:tt)*) => { let $var = read_value!($next, $t); input_inner!{$next $($r)*} }; } macro_rules! read_value { ($next:expr, ( $($t:tt),* )) => { ($(read_value!($next, $t)),*) }; ($next:expr, [ $t:tt ; $len:expr ]) => { (0..$len).map(|_| read_value!($next, $t)).collect::>() }; ($next:expr, chars) => { read_value!($next, String).chars().collect::>() }; ($next:expr, usize1) => (read_value!($next, usize) - 1); ($next:expr, [ $t:tt ]) => {{ let len = read_value!($next, usize); read_value!($next, [$t; len]) }}; ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error")); } /// Verified by https://atcoder.jp/contests/abc198/submissions/21774342 mod mod_int { use std::ops::*; pub trait Mod: Copy { fn m() -> i64; } #[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)] pub struct ModInt { pub x: i64, phantom: ::std::marker::PhantomData } impl ModInt { // x >= 0 pub fn new(x: i64) -> Self { ModInt::new_internal(x % M::m()) } fn new_internal(x: i64) -> Self { ModInt { x: x, phantom: ::std::marker::PhantomData } } pub fn pow(self, mut e: i64) -> Self { debug_assert!(e >= 0); let mut sum = ModInt::new_internal(1); let mut cur = self; while e > 0 { if e % 2 != 0 { sum *= cur; } cur *= cur; e /= 2; } sum } #[allow(dead_code)] pub fn inv(self) -> Self { self.pow(M::m() - 2) } } impl>> Add for ModInt { type Output = Self; fn add(self, other: T) -> Self { let other = other.into(); let mut sum = self.x + other.x; if sum >= M::m() { sum -= M::m(); } ModInt::new_internal(sum) } } impl>> Sub for ModInt { type Output = Self; fn sub(self, other: T) -> Self { let other = other.into(); let mut sum = self.x - other.x; if sum < 0 { sum += M::m(); } ModInt::new_internal(sum) } } impl>> Mul for ModInt { type Output = Self; fn mul(self, other: T) -> Self { ModInt::new(self.x * other.into().x % M::m()) } } impl>> AddAssign for ModInt { fn add_assign(&mut self, other: T) { *self = *self + other; } } impl>> SubAssign for ModInt { fn sub_assign(&mut self, other: T) { *self = *self - other; } } impl>> MulAssign for ModInt { fn mul_assign(&mut self, other: T) { *self = *self * other; } } impl Neg for ModInt { type Output = Self; fn neg(self) -> Self { ModInt::new(0) - self } } impl ::std::fmt::Display for ModInt { fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result { self.x.fmt(f) } } impl ::std::fmt::Debug for ModInt { fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result { let (mut a, mut b, _) = red(self.x, M::m()); if b < 0 { a = -a; b = -b; } write!(f, "{}/{}", a, b) } } impl From for ModInt { fn from(x: i64) -> Self { Self::new(x) } } // Finds the simplest fraction x/y congruent to r mod p. // The return value (x, y, z) satisfies x = y * r + z * p. fn red(r: i64, p: i64) -> (i64, i64, i64) { if r.abs() <= 10000 { return (r, 1, 0); } let mut nxt_r = p % r; let mut q = p / r; if 2 * nxt_r >= r { nxt_r -= r; q += 1; } if 2 * nxt_r <= -r { nxt_r += r; q -= 1; } let (x, z, y) = red(nxt_r, r); (x, y - q * z, z) } } // mod mod_int macro_rules! define_mod { ($struct_name: ident, $modulo: expr) => { #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)] struct $struct_name {} impl mod_int::Mod for $struct_name { fn m() -> i64 { $modulo } } } } const MOD: i64 = 1_234_567_891; define_mod!(P, MOD); type MInt = mod_int::ModInt

; // FFT (in-place, verified as NTT only) // R: Ring + Copy // Verified by: https://judge.yosupo.jp/submission/53831 // Adopts the technique used in https://judge.yosupo.jp/submission/3153. mod fft { use std::ops::*; // n should be a power of 2. zeta is a primitive n-th root of unity. // one is unity // Note that the result is bit-reversed. pub fn fft(f: &mut [R], zeta: R, one: R) where R: Copy + Add + Sub + Mul { let n = f.len(); assert!(n.is_power_of_two()); let mut m = n; let mut base = zeta; unsafe { while m > 2 { m >>= 1; let mut r = 0; while r < n { let mut w = one; for s in r..r + m { let &u = f.get_unchecked(s); let d = *f.get_unchecked(s + m); *f.get_unchecked_mut(s) = u + d; *f.get_unchecked_mut(s + m) = w * (u - d); w = w * base; } r += 2 * m; } base = base * base; } if m > 1 { // m = 1 let mut r = 0; while r < n { let &u = f.get_unchecked(r); let d = *f.get_unchecked(r + 1); *f.get_unchecked_mut(r) = u + d; *f.get_unchecked_mut(r + 1) = u - d; r += 2; } } } } pub fn inv_fft(f: &mut [R], zeta_inv: R, one: R) where R: Copy + Add + Sub + Mul { let n = f.len(); assert!(n.is_power_of_two()); let zeta = zeta_inv; // inverse FFT let mut zetapow = Vec::with_capacity(20); { let mut m = 1; let mut cur = zeta; while m < n { zetapow.push(cur); cur = cur * cur; m *= 2; } } let mut m = 1; unsafe { if m < n { zetapow.pop(); let mut r = 0; while r < n { let &u = f.get_unchecked(r); let d = *f.get_unchecked(r + 1); *f.get_unchecked_mut(r) = u + d; *f.get_unchecked_mut(r + 1) = u - d; r += 2; } m = 2; } while m < n { let base = zetapow.pop().unwrap(); let mut r = 0; while r < n { let mut w = one; for s in r..r + m { let &u = f.get_unchecked(s); let d = *f.get_unchecked(s + m) * w; *f.get_unchecked_mut(s) = u + d; *f.get_unchecked_mut(s + m) = u - d; w = w * base; } r += 2 * m; } m *= 2; } } } } mod arbitrary_mod { use crate::mod_int; use crate::fft; const MOD1: i64 = 1012924417; const MOD2: i64 = 1224736769; const MOD3: i64 = 1007681537; const G1: i64 = 5; const G2: i64 = 3; const G3: i64 = 3; define_mod!(P1, MOD1); define_mod!(P2, MOD2); define_mod!(P3, MOD3); fn zmod(mut a: i64, b: i64) -> i64 { a %= b; if a < 0 { a += b; } a } fn ext_gcd(mut a: i64, mut b: i64) -> (i64, i64, i64) { let mut x = 0; let mut y = 1; let mut u = 1; let mut v = 0; while a != 0 { let q = b / a; x -= q * u; std::mem::swap(&mut x, &mut u); y -= q * v; std::mem::swap(&mut y, &mut v); b -= q * a; std::mem::swap(&mut b, &mut a); } (b, x, y) } fn invmod(a: i64, b: i64) -> i64 { let x = ext_gcd(a, b).1; zmod(x, b) } // This function is ported from http://math314.hateblo.jp/entry/2015/05/07/014908 fn garner(mut mr: Vec<(i64, i64)>, mo: i64) -> i64 { mr.push((mo, 0)); let mut coffs = vec![1; mr.len()]; let mut constants = vec![0; mr.len()]; for i in 0..mr.len() - 1 { let v = zmod(mr[i].1 - constants[i], mr[i].0) * invmod(coffs[i], mr[i].0) % mr[i].0; assert!(v >= 0); for j in i + 1..mr.len() { constants[j] += coffs[j] * v % mr[j].0; constants[j] %= mr[j].0; coffs[j] = coffs[j] * mr[i].0 % mr[j].0; } } constants[mr.len() - 1] } // f *= g, g is destroyed fn convolution_friendly(a: &[i64], b: &[i64], gen: i64) -> Vec { use mod_int::ModInt; let d = a.len(); let mut f = vec![ModInt::

::new(0); d]; let mut g = vec![ModInt::

::new(0); d]; for i in 0..d { f[i] = a[i].into(); g[i] = b[i].into(); } let zeta = ModInt::new(gen).pow((P::m() - 1) / d as i64); fft::fft(&mut f, zeta, ModInt::new(1)); fft::fft(&mut g, zeta, ModInt::new(1)); for i in 0..d { f[i] *= g[i]; } fft::inv_fft(&mut f, zeta.inv(), ModInt::new(1)); let inv = ModInt::new(d as i64).inv(); let mut ans = vec![0; d]; for i in 0..d { ans[i] = (f[i] * inv).x; } ans } pub fn arbmod_convolution(a: &mut [i64], b: &mut [i64], mo: i64) -> Vec { use mod_int::Mod; let d = a.len(); assert!(d.is_power_of_two()); assert_eq!(d, b.len()); for x in a.iter_mut() { *x = zmod(*x, mo); } for x in b.iter_mut() { *x = zmod(*x, mo); } let x = convolution_friendly::(&a, &b, G1); let y = convolution_friendly::(&a, &b, G2); let z = convolution_friendly::(&a, &b, G3); let mut ret = vec![0; d]; let mut mr = [(0, 0); 3]; for i in 0..d { mr[0] = (P1::m(), x[i]); mr[1] = (P2::m(), y[i]); mr[2] = (P3::m(), z[i]); ret[i] = garner(mr.to_vec(), mo); } ret } } // f *= g, g is destroyed fn convolution(f: &mut [MInt], g: &[MInt]) { let mut a = vec![0; f.len()]; let mut b = vec![0; g.len()]; for i in 0..f.len() { a[i] = f[i].x; } for i in 0..g.len() { b[i] = g[i].x; } let ans = arbitrary_mod::arbmod_convolution(&mut a, &mut b, MOD); for i in 0..f.len() { f[i] = ans[i].into(); } } fn bostan_mori(a: &[MInt], b: &[MInt], mut e: i64) -> MInt { let n = a.len(); let mut len = 1; while len <= 2 * n { len *= 2; } assert_eq!(b.len(), n + 1); let mut a = a.to_vec(); let mut b = b.to_vec(); let mut c = vec![MInt::new(0); len]; let mut d = vec![MInt::new(0); len]; while e > 0 { for i in 0..2 * n + 1 { c[i] = 0.into(); } for i in 0..n + 1 { d[i] = 0.into(); } let r = (e % 2) as usize; for j in 0..n + 1 { let coef = if j % 2 == 0 { b[j] } else { -b[j] }; d[j] = coef; } for j in 0..n { c[j] = a[j]; } convolution(&mut c, &d); for i in 0..n { a[i] = c[2 * i + r]; } for i in 0..2 * n { c[i] = 0.into(); } for j in 0..n + 1 { c[j] = b[j]; } convolution(&mut c, &d); for i in 0..n + 1 { b[i] = c[2 * i]; } e /= 2; } a[0] * b[0].inv() } // Tags: bostan-mori fn main() { // In order to avoid potential stack overflow, spawn a new thread. let stack_size = 104_857_600; // 100 MB let thd = std::thread::Builder::new().stack_size(stack_size); thd.spawn(|| solve()).unwrap().join().unwrap(); } fn solve() { input! { n: usize, m: i64, a: [usize; n], } const W: usize = 25_000; let mut dp = vec![MInt::new(0); W]; dp[0] = 1.into(); let mut sz = 0; for a in a { for j in (0..W - a).rev() { dp[j + a] = dp[j + a] - dp[j]; } sz += a; } let mut tmp = vec![MInt::new(0); sz]; tmp[0] = 1.into(); println!("{}", bostan_mori(&tmp, &dp[..sz + 1], m)); }