#include using namespace std; // #include // using namespace atcoder; // //using mint = modint1000000007; // using mint = modint998244353; typedef int64_t Int; #define all(x) (x).begin(), (x).end() const double EPS = 1e-10; const Int INF = 1e18; const int inf = 1e9; //const Int mod = 1e9+7; const Int mod = 998244353; template istream &operator>>(istream &is, vector &v) { for (auto &e : v) { is >> e; } return is; } bool print_space_enable = false; void print() { std::cout << '\n'; print_space_enable = false; } template void print(Head&& head, Tail&&... tail) { if (print_space_enable) std::cout << " "; std::cout << fixed << setprecision(15) << head; print_space_enable = true; print(std::forward(tail)...); } template void print(vector v) { for (size_t i = 0; i < v.size(); i++) { if (i > 0) std::cout << " "; std::cout << v[i]; } std::cout << '\n'; } void fast_IO() { ios::sync_with_stdio(false); cin.tie(nullptr); } // 繰り返し二乗法 // x ^ p (mod m) int64_t mod_pow(int64_t x, int64_t p, int64_t m) { if (p == 0) return 1; if (p % 2 == 0) { int64_t t = mod_pow(x, p / 2, m); return t * t % m; } return x * mod_pow(x, p - 1, m) % m; } void solve() { fast_IO(); Int n, k; cin >> n >> k; vector a(n); cin >> a; Int mul = mod_pow(2, k, mod); mul = (mul - 1 + mod) % mod; Int sum = accumulate(all(a), (Int)0); Int add = sum % mod; sum %= mod; sum = sum * mul % mod; print((add + sum) % mod); } int main() { solve(); return 0; }