HEU 1008 Relatives

 1/**//**************************************
 2Problem HEU 1008 Relatives
 3Time 0.0080s
 4Memory 236 k 
 5Accepted Time 2009-03-21 21:28:24
 6Tips 欧拉函数 http://acm.hrbeu.edu.cn/forums/index.php?showtopic=2181&hl=1008 
 7**************************************/
 8#include <stdio.h>
 9int main()
{
    long n,i;
    while(scanf("%ld",&n),n!=0)
    {
        long sum=1;
        for(i=2;;i++)
        {
            if(n%i==0)
            {
                sum*=i-1;
                n/=i;
                while(n%i==0)
                {
                    n/=i;
                    sum*=i;
                }
            }
            if(n==1)break;
        }
        printf("%ld\n",sum);
    }
    return 0;
}