#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 5;
const int mod = 998244353;
long long qpow(long long a, long long b) {
  long long ans = 1;
  while (b) {
    if (b & 1) ans = ans * a % mod;
    a = a * a % mod;
    b >>= 1;
  }
  return ans;
}
int D(int x) {
  ((x >= mod) && (x -= mod)) || ((x < 0) && (x += mod));
  return x;
}
void NTT(long long a[], int n, int op) {
  for (long long i = 1, j = n >> 1; i < n - 1; ++i) {
    if (i < j) std::swap(a[i], a[j]);
    long long k = n >> 1;
    while (k <= j) {
      j -= k;
      k >>= 1;
    }
    j += k;
  }
  for (long long len = 2; len <= n; len <<= 1) {
    long long rt = qpow(3, (mod - 1) / len);
    for (long long i = 0; i < n; i += len) {
      long long w = 1;
      for (long long j = i; j < i + len / 2; ++j) {
        long long u = a[j], t = 1LL * a[j + len / 2] * w % mod;
        a[j] = D(u + t), a[j + len / 2] = D(u - t);
        w = 1LL * w * rt % mod;
      }
    }
  }
  if (op == -1) {
    std::reverse(a + 1, a + n);
    long long in = qpow(n, mod - 2);
    for (long long i = 0; i < n; ++i) a[i] = 1LL * a[i] * in % mod;
  }
}
long long a[N * 10];
int main() {
  int n, k;
  scanf("%d%d", &n, &k);
  for (int i = 1; i <= k; i++) {
    int x;
    scanf("%d", &x);
    a[x] = 1;
  }
  int len = 1;
  while (len < 5 * n) len *= 2;
  NTT(a, len, 1);
  for (int i = 0; i < len; i++) a[i] = qpow(a[i], n / 2);
  NTT(a, len, -1);
  long long ans = 0;
  for (int i = 0; i < len; i++) {
    ans += a[i] * a[i] % mod;
    ans %= mod;
  }
  printf("%lld\n", ans);
}
