#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353, inv2 = (mod + 1) / 2;
int w[1100005], WL, r[1100005];
int Pow(int a, int b) {
  int s = 1;
  for (; b; b >>= 1, a = 1ll * a * a % mod) b & 1 && (s = 1ll * s * a % mod);
  return s;
}
void init(int n) {
  w[0] = WL = 1;
  while (WL <= n) WL <<= 1;
  w[1] = Pow(3, (mod - 1) / WL);
  for (int i = 2; i <= WL; i++) w[i] = 1ll * w[i - 1] * w[1] % mod;
}
int upd(int x) { return x + (x >> 31 & mod); }
void NTT(int *a, int len, int flg) {
  for (int i = 0; i < len; i++)
    if (i < (r[i] = r[i >> 1] >> 1 | (i & 1 ? len >> 1 : 0)))
      swap(a[i], a[r[i]]);
  for (int i = 2, l = 1, v; i <= len; l = i, i <<= 1)
    for (int j = 0, t = WL / i; j < len; j += i)
      for (int k = j, o = 0; k < j + l; k++, o += t)
        a[k + l] =
            upd(a[k] - (v = 1ll * w[flg ^ 1 ? WL - o : o] * a[k + l] % mod)),
              a[k] = upd(a[k] + v - mod);
  if (flg ^ 1)
    for (int i = 0, Inv = mod - (mod - 1) / len; i < len; i++)
      a[i] = 1ll * a[i] * Inv % mod;
}
int n, k, a[1100005];
int main() {
  scanf("%d%d", &n, &k);
  for (int i = 1, x; i <= k; i++) scanf("%d", &x), a[x] = 1;
  init(n / 2 * 9);
  NTT(a, WL, 1);
  for (int i = 0; i < WL; i++) a[i] = Pow(a[i], n / 2);
  NTT(a, WL, -1);
  int ans = 0;
  for (int i = 0; i < WL; i++) ans = (ans + 1ll * a[i] * a[i]) % mod;
  printf("%d\n", ans);
}
