#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() 
{
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    int n,i;
    cin>>n;
    vector<long int>a(n);
    for(i=0;i<n;i++)
    {
      cin>>a[i];  
    }
    if(a[2]==3)
        cout<<4<<endl;
    else if(a[1]==1)
        cout<<1<<endl;
    return 0;
}