func_code_string: #include <bits/stdc++.h>   using namespace std;   const long long mod = 998244353;   long long po[1000006];   long long sr[1000006];   long long a[1000006];   int main() {     ios_base::sync_with_stdio(false);     cin.tie(0);     po[0] = 1;     sr[0] = 1;     for (int i = 1; i <= 1000002; i++) {       po[i] = po[i - 1] * 2;       po[i] %= mod;     }     sr[1] = 3;     for (int i = 2; i <= 1000002; i++) {       sr[i] = ((i + 2) * po[i - 1]) % mod;     }     long long n;     cin >> n;     for (int i = 0; i < n; i++) cin >> a[i];     int pos = 0;     long long ret = 0;     for (int i = n - 1; i >= 0; i--) {       long long co = sr[pos++];       long long temp = (co * a[i]) % mod;       ret += temp;       ret %= mod;     }     cout << ret << endl;   }   