#include <bits/stdc++.h>
using namespace std;
long long mod = 998244353;
long long powmod(long long x, long long y, long long m) {
  if (y == 0) return 1;
  if (y % 2) return (x * powmod(x, y - 1, m)) % m;
  return powmod((x * x) % m, y / 2, m);
}
long long inv(long long b, long long M) {
  long long u = 1, x = 0, s = b, t = M;
  while (s) {
    long long q = t / s;
    swap(x -= u * q, u);
    swap(t -= s * q, s);
  }
  return (x %= M) >= 0 ? x : x + M;
}
const int G = 3;
void fmt(vector<long long> &x, int sign = +1) {
  int n = x.size();
  for (int i = 0, j = 1; j < n - 1; ++j) {
    for (int k = n >> 1; k > (i ^= k); k >>= 1)
      ;
    if (j < i) swap(x[i], x[j]);
  }
  long long h = powmod(G, (mod - 1) / n, mod);
  if (sign < 0) h = inv(h, mod);
  for (int m = 1; m < n; m *= 2) {
    long long w = 1, wk = powmod(h, n / (2 * m), mod);
    for (int i = 0; i < m; ++i) {
      for (int j = i; j < n; j += 2 * m) {
        long long u = x[j], d = (x[j + m] * w) % mod;
        x[j] = (u + d) % mod;
        x[j + m] = (u - d + mod) % mod;
      }
      w = w * wk % mod;
    }
  }
  if (sign < 0) {
    long long n_inv = inv(n, mod);
    for (auto &a : x) a = (a * n_inv) % mod;
  }
}
vector<long long> s;
int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  long long a, n;
  int k;
  cin >> n >> k;
  int l = 2;
  while (l < 1000000) l <<= 1;
  s = vector<long long>(l, 0);
  for (int i = 1; i <= k; i++) {
    cin >> a;
    s[a] = 1;
  }
  fmt(s, 1);
  for (int i = 0; i < l; i++) s[i] = powmod(s[i], n >> 1, mod);
  fmt(s, -1);
  long long sol = 0;
  for (int i = 0; i < l; i++) {
    long long s1 = s[i];
    sol += (s1 * s1) % mod;
    sol %= mod;
  }
  cout << sol << endl;
  return 0;
}
