View Code of Problem 73

#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    int n,sum=1;
	scanf("%d",&n);
	for(int i=1;i<n;i++)
	{
			sum=(sum+1)*2;
	}
	 printf("%d\n",sum);
	return 0;

}