#include "stdio.h"
int main()
{
int n,sum=1,i;
while( scanf("%d",&n)!=EOF)
{
if( n<=1 || n>=30 )
break;
else
{
for( i=n; i>0; i-- )
{
sum = (sum+1)*2;
}
}
printf("%d\n",sum);
}
}