#include<bits/stdc++.h> using namespace std; int main(){ int n,i,s = 1,a[1000]; cin>>n; a[1] = 3; a[2] = 7; for(i = 3;i <= n;i++){ a[i] = a[i - 1] * a[i - 2]; s = a[i]; } cout<<s<<endl; }