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