#include <bits/stdc++.h>
using namespace std;
const long long mxsz = 4e6 + 5;
const long long mod = 998244353;
long long n, k;
long long d[15];
long long arr[mxsz], r[mxsz];
long long fpow(long long b, long long e) {
  long long ret = 1LL;
  for (; e > 0; e >>= 1) {
    if (e & 1) {
      ret *= b;
      ret %= mod;
    }
    b *= b;
    b %= mod;
  }
  return ret;
}
void ntt(long long *a, long long N, long long root) {
  for (long long i = 0; i < N; i++)
    if (i < r[i]) swap(a[i], a[r[i]]);
  for (long long i = 1; i < N; i <<= 1) {
    long long r = fpow(root, (mod - 1) / (i << 1));
    for (long long j = 0; j < N; j += (i << 1)) {
      for (long long k = 0, t = 1; k < i; k++, t = (t * r) % mod) {
        long long x1 = a[j + k], x2 = (a[i + j + k] * t) % mod;
        a[j + k] = (x1 + x2) % mod;
        a[i + j + k] = (x1 + mod - x2) % mod;
      }
    }
  }
}
int32_t main() {
  cin >> n >> k;
  long long mx = 0;
  for (long long i = 0; i < k; i++) {
    cin >> d[i];
    mx = max(mx, d[i]);
    arr[d[i]] = 1;
  }
  n /= 2;
  long long N = 1, sh = -1;
  while (N <= (n * 10)) {
    N <<= 1;
    sh++;
  }
  for (long long i = 0; i < N; i++) r[i] = (r[i >> 1] >> 1) | ((i & 1) << sh);
  ntt(arr, N, 3);
  for (long long i = 0; i < N; i++) arr[i] = fpow(arr[i], n);
  ntt(arr, N, (mod + 1) / 3);
  long long inv = fpow(N, mod - 2);
  long long ans = 0;
  for (long long i = 0; i < N; i++) arr[i] = (arr[i] * inv) % mod;
  for (long long i = 0; i < N; i++) {
    ans += (arr[i] * arr[i]) % mod;
    ans %= mod;
  }
  cout << ans << '\n';
  return 0;
}
