#include <bits/stdc++.h>
using namespace std;
const int N = 4000005, mod = 998244353;
int n, k, rev[N], ans;
int qp(int a, int b) {
  int ans = 1;
  while (b) {
    if (b & 1) ans = 1ll * ans * a % mod;
    a = 1ll * a * a % mod;
    b >>= 1;
  }
  return ans;
}
void ntt(vector<int>& a, int f) {
  int n = a.size();
  for (int i = 0; i < n; i++)
    if (i < rev[i]) swap(a[i], a[rev[i]]);
  for (int i = 1; i < n; i <<= 1) {
    int wn = qp(f ? (mod + 1) / 3 : 3, (mod - 1) / (i << 1));
    for (int j = 0; j < n; j += (i << 1)) {
      int w = 1;
      for (int k = 0; k < i; k++, w = 1ll * w * wn % mod) {
        int x = a[j + k], y = 1ll * w * a[j + k + i] % mod;
        a[j + k] = (x + y >= mod ? x + y - mod : x + y);
        a[j + k + i] = (x - y < 0 ? x - y + mod : x - y);
      }
    }
  }
  if (f) {
    int iv = qp(n, mod - 2);
    for (int i = 0; i < n; i++) a[i] = 1ll * a[i] * iv % mod;
  }
}
vector<int> mul(vector<int> x, vector<int> y) {
  int n = 1, l = 0, m = x.size() + y.size() - 1;
  while (n < m) n <<= 1, l++;
  for (int i = 0; i < n; i++)
    rev[i] = (rev[i >> 1] >> 1) | ((i & 1) << (l - 1));
  x.resize(n), y.resize(n);
  ntt(x, 0), ntt(y, 0);
  for (int i = 0; i < n; i++) x[i] = 1ll * x[i] * y[i] % mod;
  ntt(x, 1);
  x.resize(m);
  return x;
}
vector<int> qp(vector<int> a, int b) {
  vector<int> ans = {1};
  while (b) {
    if (b & 1) ans = mul(ans, a);
    a = mul(a, a);
    b >>= 1;
  }
  return ans;
}
int main() {
  scanf("%d%d", &n, &k);
  n /= 2;
  vector<int> a(10, 0);
  for (int i = 1; i <= k; i++) {
    int x;
    scanf("%d", &x);
    a[x] = 1;
  }
  a = qp(a, n);
  for (int i = 0; i < a.size(); i++)
    ans = (ans + 1ll * a[i] * a[i] % mod) % mod;
  printf("%d\n", ans);
  return 0;
}
