/*
TASK: necklace
LANG: C++
*/
#include <iostream>
using namespace std;

int N;

int A[5] = {0,1,1,3,5};

unsigned long long bck(int i)
{
    if(i<=4) {return A[i-1];}
    if(i%2==0) {return 2*bck(i-1)+1;}
    else
    {
        return 2*bck(i-1)-1;
    }
}

int main()
{
    cin>>N;
    cout<<bck(N)<<'\n';
    return 0;
}
            
