func_code_string: #include <bits/stdc++.h>   using namespace std;   long long ans;   int main() {     int n, i;     long long a;     cin >> n;     ans = 0;     for (i = 1; i <= n; i++) {       cin >> a;       ans = ans + (1 + (a - 1) * (long long)i);     }     cout << ans << endl;     return 0;   }   