//My solution using bottom up approach.

#include <bits/stdc++.h>
using namespace std;
 
long long n;
long long a[200005] = {0};
long long dp[200005] = {0};
 
int main()
{
 cin >> n;
 
 for(int i=0; i<n; i++)
 {
 cin >> a[n-i-1]; //Reverse order.
 }
 
    dp[0] = a[0];
    dp[1] = a[1];
    dp[2] = a[2];