l1.cpp

#include <iostream>

using namespace std;

uintmax_t arr[74][74];


uintmax_t bs(int a,int b) {
	uintmax_t ans=0;
	for (int i = 1; i <=b; ++i)
	{
		if(arr[a-1][i]==0)
			arr[a-1][i]=bs(a-1,i);
		ans+=arr[a-1][i];
	}
	return ans;
}

int main() {

	int t;
	cin>>t;
	//long long arr[t+1][t]{0};
	for (int i = 0; i < t; ++i)
	{
		arr[1][i]=i;
	}
	for (int i = 0; i <= t; ++i)
	
	{	arr[i][1]=1;
	}
	cout<<bs(t,t-1)<<endl;

}