#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,x;
    cin >> n;
    for(int i = 0 ; i < n ; i++)
        {
        cin >> x;
    }
    cout << pow(2,n)/2 << endl;
    
    return 0;
}