mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-11-14 04:58:49 +00:00
11 lines
157 B
C++
11 lines
157 B
C++
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
|
|
int main() {
|
|
long long n, k;
|
|
cin >> n >> k;
|
|
cout << n * (n - 1) / 2 - k << endl;
|
|
return 0;
|
|
}
|