#include <bits/stdc++.h>

using namespace std;

using i64 = long long;

const long long MOD = 1000000007;
const i64 INF = i64(1e18) + 7;

void solve(long long n, std::vector<long long> x){

	int cnt = 0;
    int m = n - 1;
    for(int j = 0; j < n; ++j){
        if(1 == j + 1)
            continue;
        for(int i = 0; i < j; ++i){
            cnt = cnt * 2 - (cnt + 1) * cnt;
        }
    }
    cout << cnt << endl;
}


signed main(){
    long long N;
    scanf("%lld",&N);
    std::vector<long long> x(N);
    for(int i = 0 ; i < N ; i++){
        scanf("%lld",&x[i]);
    }
    solve(n, x);
    return 0;
}
