1 #include<stdio.h>
 2 int main()
 3 {
 4     int n,s,i;
 5     while(~scanf("%d",&n))
 6     {
 7         for(i=s=1; i<n; ++i)
 8             s=(s+1)*2;
 9         printf("%d\n",s);
10     }
11     return 0;
12 }