Files
HuangHai 1f397eca87 'commit'
2025-08-30 18:35:01 +08:00

13 lines
171 B
C++

#include<bits/stdc++.h>
using namespace std;
double n, res = 0.00;
int main() {
cin >> n;
res = n * n / 4;
printf("%.2f", res);
return 0;
}