#include <iostream>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <tuple>
#include <cmath>
#include <numeric>
#include <functional>
#include <cassert>
#include <atcoder/modint>
#include <atcoder/convolution>

#define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl;
#define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }

using namespace std;
typedef long long ll;

template<typename T>
vector<vector<T>> vec2d(int n, int m, T v){
    return vector<vector<T>>(n, vector<T>(m, v));
}

template<typename T>
vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){
    return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v)));
}

template<typename T>
void print_vector(vector<T> v, char delimiter=' '){
    if(v.empty()) {
        cout << endl;
        return;
    }
    for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter;
    cout << v.back() << endl;
}

using mint = atcoder::modint998244353;

#define N_MAX 200002
mint fac[N_MAX];

void init(){
    fac[0]=1;fac[1]=1;
    for(int i=2;i<N_MAX;i++){
        fac[i]=fac[i-1]*(ll) i;
    }
}


ostream& operator<<(ostream& os, const mint& m){
    os << m.val();
    return os;
}


vector<mint> calc(vector<vector<mint>> v){
    if(v.size() == 1) return v[0];
    int n = v.size();
    vector<vector<mint>> vl, vr;
    for(int i = 0; i < n; i++){
        if(i*2 < n) vl.push_back(v[i]);
        else vr.push_back(v[i]);
    }
    return atcoder::convolution(calc(vl), calc(vr));
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << setprecision(10) << fixed;
    init();
    int n, s; cin >> n >> s;
    mint s_inv = mint(s).inv();
    vector<mint> p(n);
    vector<vector<mint>> v(n);
    for(int i = 0; i < n; i++){
        int x; cin >> x;
        p[i] = s_inv*x;
        v[i] = {mint(1), p[i]};
    }
    auto u = calc(v);
    // print_vector(u);
    mint ans = 0;
    for(int k = 1; k <= n; k++){
        mint tmp = u[k];
        if(k != n) tmp -= u[k+1]*(k+1);
        tmp *= fac[k];
        ans += tmp*(k+1);
        // cout << k << ':' << tmp << endl;
    }
    cout << ans.val() << endl;
}