func_code_string: #include <iostream>   #include <algorithm>   using namespace std;         int main()   {       int64_t k;       int64_t n, x, t;       cin >> k;       while(k--) {           cin >> n >> x >> t;           int64_t zero = 0;           int64_t ans = max(zero, n - t/x) * (t / x) + min(t/x, n) * min(t/x - 1, n - 1) / 2;           cout << ans << endl;       }             return 0;   }   