#include<iostream>

 #include<cstring>

 #include<cstdio>

 using namespace std;

 int n,ans;

 void dfs(int x)

 {

     if(x==){

         ans++;return ;

     }

     else if(x<&&x!=) return;

     dfs(x-);

     dfs(x-);

 }

 int main()

 {

     scanf("%d",&n);

     dfs(n);

     printf("%d",ans);

     return ;

 }

 #include<cstdio>

 #define ll long long

 using namespace std;

 ll f[];

 int main() {

     int n;

     scanf("%d", &n);

     f[]=; f[]=f[]=;

     for(int i=;i<=n;i++) f[i]=f[i-]+f[i-];

     printf("%lld\n", f[n]);

     return ;

 }

 // 这题居然是递推！！！！！！