1182A - Filling Shapes - CodeForces Solution

#include <iostream>
#include <algorithm>
#include <math.h>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <vector>
#define ll long long
#define pp pop_back
#define sz s.size()
#define N 10005
#define ff first
#define ss second
#define pb push_back
using namespace std;

long long t, n, a[N], b[N], c, cnt, ind, d, e;

int main()
{
	cin >> n;
	c = 1;
	if(n % 2 == 0){
		n /= 2;
		while( n-- ){
			c *= 2;
		}

		cout << c;
	}

	else {
		cout << 0;
	}
}