View Code of Problem 73

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