Friend

Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 2678    Accepted Submission(s): 1389

Problem Description

Friend number are defined recursively as follows.
(1) numbers 1 and 2 are friend number;
(2) if a and b are friend numbers, so is ab+a+b;
(3) only the numbers defined in (1) and (2) are friend number.
Now your task is to judge whether an integer is a friend number.

Input

There are several lines in input, each line has a nunnegative integer a, 0<=a<=2^30.

Output

For the number a on each line of the input, if a is a friend number, output “YES!”, otherwise output “NO!”.

Sample Input

3

13121

12131

Sample Output

YES!

YES!

NO!

#include <stdio.h>
    int main()
    {
        __int64 n;
        while(~scanf("%I64d",&n))
        {
            if(!n)
            {
                printf("NO!\n");
                continue;
            }
            n++;
            while(n%2==0)
                n/=2;
            while(n%3 == 0)
                n/=3;
            if(n==1)
                printf("YES!\n");
            else
                printf("NO!\n");
        }  

        return 0;
    }