#include <bits/stdc++.h>
using namespace std;
using ll=long long;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}

#include <atcoder/modint>
using mint = atcoder::modint998244353;

struct F{
    mint c = 0;
    mint v = 0;
};

F operator*(F a, F b){
    return {a.c * b.c, a.c * b.v + a.v * b.c};
}
F operator+(F a, F b){
    return {a.c + b.c, b.v + a.v};
}

void solve();
// DEAR MYSTERIES / TOMOO
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    int N, K;
    cin >> N >> K;
    vector<int> A(N);
    rep(i, 0, N) cin >> A[i];
    vector<F> dp1(K + 1), dp2(K + 1);
    dp1[0] = {1, 0};
    rep(rp, 0, N){
        for (int i = K; i > 0; i--){
            dp2[i - 1] = dp2[i - 1] + dp2[i];
        }
        dp2[K] = dp2[K] + dp1[K];
        dp1[K] = {0, 0};
        rep(i, 0, K){
            dp1[i + 1] = dp1[i + 1] + dp1[i];
        }
        mint p2 = 1, pa = 1;
        rep(i, 0, K + 1){
            F tmp = {p2, pa * p2};
            dp1[i] = dp1[i] * tmp;
            dp2[i] = dp2[i] * tmp;
            p2 *= 2, pa *= A[rp];
        }
    }
    mint ans = 0;
    rep(i, 0, K + 1) ans += dp2[i].v;
    ans /= (mint(4)).pow(K);
    cout << ans.val() << "\n";
}