#include <bits/stdc++.h>
using namespace std;
const int mod = 998244353;
const int NN = 1 << 20;
int qpow(int a, int b) {
  int ret = 1;
  while (b) {
    if (b & 1) ret = (long long)ret * a % mod;
    a = (long long)a * a % mod;
    b >>= 1;
  }
  return ret;
}
namespace NTT {
const int g = 3;
int x[NN << 2], y[NN << 2], wn[NN << 2];
void init() {
  for (int i = 0; i <= 20; i++) wn[i] = qpow(g, (mod - 1) / (1 << i));
}
void brc(int *F, int len) {
  int j = len / 2;
  for (int i = 1; i <= len - 2; i++) {
    if (i < j) swap(F[i], F[j]);
    int k = len / 2;
    while (j >= k) j -= k, k >>= 1;
    if (j < k) j += k;
  }
}
void NTT(int *F, int len, int t) {
  int id = 0;
  brc(F, len);
  for (int h = 2; h <= len; h <<= 1) {
    id++;
    for (int j = 0; j < len; j += h) {
      int E = 1;
      for (int k = j; k < j + h / 2; k++) {
        int u = F[k], v = (long long)E * F[k + h / 2] % mod;
        F[k] = (u + v) % mod, F[k + h / 2] = ((u - v) % mod + mod) % mod;
        E = (long long)E * wn[id] % mod;
      }
    }
  }
  if (t == -1) {
    for (int i = 1; i <= len / 2 - 1; i++) swap(F[i], F[len - i]);
    long long inv = qpow(len, mod - 2);
    for (int i = 0; i <= len - 1; i++) F[i] = (long long)F[i] % mod * inv % mod;
  }
}
}  // namespace NTT
int a[NN], n, k;
int main() {
  NTT::init();
  scanf("%d%d", &n, &k);
  for (int i = 1; i <= k; i++) {
    int x;
    scanf("%d", &x);
    a[x] = 1;
  }
  NTT::NTT(a, 1 << 20, 1);
  for (int i = 0; i < (1 << 20); i++) a[i] = qpow(a[i], n / 2);
  NTT::NTT(a, 1 << 20, -1);
  int ans = 0;
  for (int i = 0; i <= 9 * n / 2; i++) ans = (ans + 1ll * a[i] * a[i]) % mod;
  printf("%d\n", ans);
  return 0;
}
