📅  最后修改于: 2022-03-11 14:44:53.889000             🧑  作者: Mango
#include
using namespace std;
int main()
{
long long n, sum;
cin >> n;
if (n % 2 == 0)
sum = (n / 2);
else
sum = ((n + 1) / 2) * (-1);
cout << sum << endl;
return 0;
}