#pragma GCC optimize("Ofast,unroll-loops")
#include <iostream>
#include <vector>
using namespace std;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)

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

int main() {
    cin.tie(nullptr), ios::sync_with_stdio(false);
    int N, K;
    cin >> N >> K;
    vector<int> A(N);
    for (auto &x : A) cin >> x;

    vector<mint> pow2(K * 2 + 10, 1);
    FOR(i, 1, pow2.size()) pow2[i] = pow2[i - 1] * 2;

    vector dpn(3, vector<mint>(K + 1));
    vector dpsum(3, vector<mint>(K + 1));
    dpn[0][0] = pow2[K * 2].inv();

    vector<mint> ap(K + 1, 1);
    REP(i, N) {
        FOR(k, 1, K + 1) ap[k] = ap[k - 1] * A[i];

        REP(k, K) {
            dpsum[0][k + 1] += dpsum[0][k];
            dpn[0][k + 1] += dpn[0][k];
        }

        IREP(k, K) {
            dpsum[2][k] += dpsum[2][k + 1];
            dpn[2][k] += dpn[2][k + 1];
        }

        REP(d, 3) REP(k, K + 1) {
            dpsum[d][k] = (dpsum[d][k] + dpn[d][k] * ap[k]) * pow2[k];
            dpn[d][k] *= pow2[k];
        }
        IREP(d, 2) {
            dpsum[d + 1][K] += dpsum[d][K];
            dpn[d + 1][K] += dpn[d][K];
            dpsum[d][K] = dpn[d][K] = 0;
        }
    }
    cout << accumulate(dpsum.back().begin(), dpsum.back().end(), mint(0)).val() << '\n';
}