#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef long long ll;
const int N = 2000086, MOD = 998244353, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];


inline ll qmi(ll a, ll b, ll c) { ll res = 1; while (b) { if (b & 1) res = res * a % c; a = a * a % c; b >>= 1; } return res; }

int main() {
    cin >> n >> m;
    for (int i = 1; i < n + 1; i++) scanf("%d", w + i);
    ll sum1 = 1, sum2 = 1;
    for (int i = 1; i < n + 1; i++) {
        int c = min(m, w[i]);
        sum1 = sum1 * c % MOD * qmi(w[i], MOD - 2, MOD) % MOD;
    }
    for (int i = 1; i < n + 1; i++) {
        int c = min(m - 1, w[i]);
        sum2 = sum2 * c % MOD * qmi(w[i], MOD - 2, MOD) % MOD;
    }
    printf("%lld\n", (sum1 - sum2 + MOD) % MOD);
    return 0;
}