#include<cmath>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
int n,ans;
int read()
{
    ,f=; char ch=getchar();
    ; ch=getchar();}
    +ch-'; ch=getchar();}
    return x*f;
}
void dfs(int now,int s,int l)
{
    if(l==n) {ans++;return ;}
    ) dfs(now,s+,l+);
    dfs(now^,,l+);
}
int main()
{
    n=read();
    ) ans=;
    ,,),dfs(,,);
    printf("%d",ans);
}