#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using mint = atcoder::modint998244353;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, k, v, sv = 0, f = 0;
    cin >> n >> k;
    vector<vector<int>> tb(n / 3 + 1);
    tb[0].emplace_back(0);
    for(int i = 0; i < n; i++){
        cin >> v;
        sv += (abs(v) == 2);
        f ^= (v < 0);
        if(sv % 3 == 0 && f == 0){
            tb[sv / 3].emplace_back(i + 1);
        }
    }
    vector<mint> dp(n + 1), dp2(n + 1), len(n + 1);
    for(int i = 1; i <= n; i++) len[i] = mint::raw(i).pow(k);
    dp[0] = 1;
    for(int i = 0; i + 1 < tb.size(); i++){
        if(tb[i + 1].empty()) break;
        int l = tb[i][0], r0 = tb[i].back() + 1;
        vector<mint> tmp{dp.begin() + l, dp.begin() + r0};
        vector<mint> coef{len.begin(), len.begin() + (tb[i + 1].back() - l + 1)};
        mint sv1 = accumulate(dp.begin() + l, dp.begin() + r0, mint(0));
        mint sv2 = accumulate(dp2.begin() + l, dp2.begin() + r0, mint(0));
        auto add = convolution(tmp, coef);
        for(auto p : tb[i + 1]){
            dp2[p] = add[p - l] + sv2;
            dp[p] = sv1;
        }
    }
    cout << dp2[n].val() << '\n';
}