func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     int n, i;     long long a, b;     cin >> n;     i = a = 0, b = 1000000001;     int arr[n];     while (i < n) {       cin >> arr[i];       i++;     }     i = n - 1;     while (i >= 0) {       if (arr[i] < b) {         a += arr[i];         b = arr[i];         if (b == 1) break;       } else if (arr[i] >= b) {         b--;         a += b;         if (b == 1) break;       }       i--;     }     cout << a << endl;     return 0;   }   