View Code of Problem 73

#include <stdio.h>
int main()
{
	int N;
	int i;
	int sum;
	scanf("%d",&N);
	sum = 1;
	for(i = 1;i<N;i++)
	{
		sum = (sum + 1)*2; 
		
	}
	
	printf("%d",sum);
	return 0;
}