#include <bits/stdc++.h>
template <class T>
void read(T &x) {
  x = 0;
  int f = 0;
  char ch = getchar();
  while (ch < '0' || ch > '9') f |= (ch == '-'), ch = getchar();
  while (ch <= '9' && ch >= '0')
    x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
  x = f ? -x : x;
  return;
}
const int maxn = 2e5 + 7, p = 998244353, G = 3;
int ksm(int a, int b) {
  int r = 1;
  while (b) {
    if (b & 1) r = (long long)r * a % p;
    a = (long long)a * a % p;
    b >>= 1;
  }
  return r;
}
int s, invs, a[maxn * 10], rev[maxn * 10];
void NTT(int *a, int flag) {
  for (int i = 0; i < s; i++)
    if (i < rev[i]) std::swap(a[i], a[rev[i]]);
  for (int len = 1; len < s; len <<= 1) {
    int w = ksm(G, (p - 1) / (len << 1));
    if (flag == -1) w = ksm(w, p - 2);
    for (int i = 0; i < s; i += (len << 1)) {
      int aw = 1, u, v;
      for (int j = 0; j < len; j++) {
        u = a[i + j];
        v = (long long)a[i + j + len] * aw % p;
        a[i + j] = (u + v) % p;
        a[i + j + len] = (u - v + p) % p;
        aw = (long long)aw * w % p;
      }
    }
  }
  if (flag == -1)
    for (int i = 0; i < s; i++) a[i] = (long long)a[i] * invs % p;
}
int main() {
  int n, k;
  read(n);
  read(k);
  for (int i = 1; i <= k; i++) {
    int x;
    read(x);
    a[x] = 1;
  }
  s = 1048576;
  invs = ksm(s, p - 2);
  for (int i = 1; i < s; i++)
    rev[i] = (rev[i >> 1] >> 1) | ((i & 1) * (s >> 1));
  NTT(a, 1);
  for (int i = 0; i < s; i++) a[i] = ksm(a[i], n >> 1);
  NTT(a, -1);
  int ans = 0;
  for (int i = 0; i < s; i++) ans = (ans + (long long)a[i] * a[i] % p) % p;
  printf("%d\n", ans);
  return 0;
}
