#![allow(non_snake_case, unused_imports, unused_must_use)] use std::io::{self, prelude::*}; use std::str; fn main() { let (stdin, stdout) = (io::stdin(), io::stdout()); let mut scan = Scanner::new(stdin.lock()); let mut out = io::BufWriter::new(stdout.lock()); macro_rules! input { ($T: ty) => { scan.token::<$T>() }; ($T: ty, $N: expr) => { (0..$N).map(|_| scan.token::<$T>()).collect::>() }; } let N = input!(usize); let P = input!(usize); let Q = input!(usize); let mut A = input!(usize, N); A.sort(); let mut cnt = 0; for i in 0..N { let v1 = pow(10, A[i], P); for j in i + 1..N { let v2 = pow(9, A[j], P); for k in j + 1..N { let v3 = pow(7, A[k], P); for l in k + 1..N { let v4 = pow(5, A[l], P); if (v1 + v2 + v3 + v4) % P == Q { cnt += 1; } } } } } writeln!(out, "{}", cnt); } pub fn pow(a: usize, b: usize, m: usize) -> usize { let mut ret = 1; let mut p = a; for i in 0..61 { if (b >> i) & 1 == 1 { ret *= p; ret %= m; } p *= p; p %= m; } return ret; } struct Scanner { reader: R, buf_str: Vec, buf_iter: str::SplitWhitespace<'static>, } impl Scanner { fn new(reader: R) -> Self { Self { reader, buf_str: vec![], buf_iter: "".split_whitespace(), } } fn token(&mut self) -> T { loop { if let Some(token) = self.buf_iter.next() { return token.parse().ok().expect("Failed parse"); } self.buf_str.clear(); self.reader .read_until(b'\n', &mut self.buf_str) .expect("Failed read"); self.buf_iter = unsafe { let slice = str::from_utf8_unchecked(&self.buf_str); std::mem::transmute(slice.split_whitespace()) } } } }