You have a given integer n. Find the number of ways to fill all 3×n tiles with the shape described in the picture below. Upon filling, no empty spaces are allowed. Shapes cannot overlap.

This picture describes when n=4. The left one is the shape and the right one is 3×n tiles.
Input
The only line contains one integer n (1≤n≤60) — the length.

Output
Print the number of ways to fill.

Examples
inputCopy
4
outputCopy
4
inputCopy
1
outputCopy
0
Note
In the first example, there are 4 possible cases of filling.

In the second example, you cannot fill the shapes in 3×1 tiles.

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<ctime>
#include<iostream>
#include<algorithm>
#include<map>
#include<stack>
#include<queue>
#include<vector>
#include<set>
#include<string>
#define ll long long
#define dd double
using namespace std;

int main() {
	ios::sync_with_stdio(false);
	ll n; cin >> n;
	if (n % 2 == 1) {
		cout << "0" << endl;
	}
	else {
		ll p;
		p = pow(2, n / 2);
		cout << p << endl;
	}
}