View Code of Problem 73

#include<iostream>
#include<cstring>
#include<string>
#include<algorithm>
#include<vector>
using namespace std;

int main()
{
	int n;
	int sum = 1;
	cin >> n;
	for (int i = 0; i < n-1; i++) {
		sum = 2 * (sum + 1);
	}
	cout << sum;
	return 0;
}