GESP二级编程题1

#include <iostream>
using namespace std;

int main() {
int n;
cin >> n;
int count = 0;

for (int a = 1; a <= n; a++) {
    for (int b = a; b <= n; b++) {
        if ((a * b) % 2 == 0) {
            count++;
        }
    }
}

cout << count << endl;
return 0;

}