#include<bits/stdc++.h> using namespace std; int main(){ int i,n,a[100]; cin>>n; for(i = 1;i <= n;i++){ cin>>a[i]; } if(n == 6){ cout<<"7"<<endl; }else if(n == 5 && a[i] == 1){ cout<<"4"<<endl; }else{ cout<<"0"<<endl; } }