func_code_string: #include <bits/stdc++.h>   #pragma comment(linker,  /stack:200000000 )   #pragma GCC optimize( Ofast )   #pragma GCC target( sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native )   using namespace std;   template <typename Arg1>   void __f(const char* name, Arg1&& arg1) {     cerr << name <<   :   << arg1 << std::endl;   }   template <typename Arg1, typename... Args>   void __f(const char* names, Arg1&& arg1, Args&&... args) {     const char* comma = strchr(names + 1,  , );     cerr.write(names, comma - names) <<   :   << arg1 <<   |  ;     __f(comma + 1, args...);   }   void pre() {}   void solve() {}   const long long mod = 998244353;   long long pw[1000009], a[1000009];   int main() {     cin.sync_with_stdio(0);     cin.tie(0);     cin.exceptions(cin.failbit);     pre();     pw[0] = 1;     for (int i = 1; i <= (1000000); ++i) pw[i] = pw[i - 1] * 2 % mod;     int n;     cin >> n;     for (int i = 0; i < (n); ++i) cin >> a[i + 1];     long long ans = a[n];     for (int i = 1; i <= (n - 1); ++i) {       ans += 1ll * pw[n - i] * a[i] % mod;       ans += 1ll * (n - i) * a[i] % mod * pw[n - 1 - i] % mod;     }     cout << ans % mod;     return 0;   }   