#include<iostream>
using namespace std;

int main() {
	int a;
	int b;
	int c;
	int d;
	int mid=1;
	int ans=0;

	cin >> a;
	b = a / 2;
	c = a / 2;
	d = a / 2;



	if (a % 2 == 0) {
		for (int i = 0; i <= c; i++) {
			for (int j = 0; j < d; j++) {
				mid = mid * (d - j);
			}
			for (int k = 0; k < b; k++) {
				mid = mid / (b - k);
			}
			for (int l = 0; l < d - b; l++) {
				mid = mid / (d - b - l);
			}
			ans = ans + mid;
			mid = 1;

			d++;
			b--;
		}
		
	}
	if (a % 2 == 1) {
		d++;
		for (int i = 0; i <= c; i++) {
			for (int j = 0; j < d; j++) {
				mid = mid * (d - j);
			}
			for (int k = 0; k < b; k++) {
				mid = mid / (b - k);
			}
			for (int l = 0; l < d - b; l++) {
				mid = mid / (d - b - l);
			}
			ans = ans + mid;
			mid = 1;

			d++;
			b--;
		}
		
	}
	cout << ans;
	return 0;
}