func_code_string: #include <iostream>   #include <vector>   #include <set>    #include <algorithm>   #include<map>   #include <math.h>   using namespace std;   void solve(){      int n,x,t;      cin>>n>>x>>t;      cout<<(long long)max(0,n-t/x)*(t/x) + (long long)min(n,t/x)*min(n-1,t/x-1)/2<<endl;          }      int main()   {   #ifndef ONLINE_JUDGE       freopen( input.txt ,  r , stdin);       freopen( output.txt ,  w , stdout);   #endif       ios_base::sync_with_stdio(false);       cin.tie(NULL);          int testCase;       cin>>testCase;       while (testCase--)       {           solve();       }          }