#include<bits/stdc++.h>
using namespace std;
#define miao int
#define miaomiao main
#define mi (
#define ao )
#define miiao cin
#define miaoo for
#define mmiao =
#define bigger ++
#define smaller --
#define big +
#define small -
#define miaoa
miao miaomiao mi ao
{
	miao fish,ans mmiao 1;
	miiao>>fish;
	miaoo mi miao fish2 mmiao 1;fish2<=fish;fish2 bigger ao
	{
		miaoo mi miao fish3 mmiao 0;fish3<fish2;fish3 bigger ao
		{
			ans big mmiao fish2;
		}
	}
	miaoa<<ans;
}