View Code of Problem 73

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