HDU 2013

#include<stdio.h> int main(){ int n= 0; while(scanf("%d",&n)!= EOF){ //printf("n:%d\n",n); int result =1; for(int i=0;i<n-1;i++){ result = (result +1)*2; //printf("%d\n",i); //printf("%d\n",result); } printf("%d\n",result); } return 0; }