#include <iostream>
using namespace std; 
int f(int i){
	int n=7;
	if(n==1){
		return i;}
	else {
		return f(n-1)+f(n-1)+4; }
}
int main(){  
	int i;                                  
	cin>>i;
	cout<<f(i);
	return 0;
}
/**************************************************************
	Problem: 1688
	User: panyuchen
	Language: C++
	Result: Memory Limit Exceed
****************************************************************/