View Code of Problem 73

#include <stdio.h>
#include <stdlib.h>
#include<ctype.h>
#include<string.h>
#include<math.h>

int main()
{
	int n, i,sum=1;
	scanf("%d", &n);
	for (i = n - 1; i > 0; i--)
	{
		sum = (sum + 1) * 2;
	}
	printf("%d", sum);
	return 0;
}