Contest 2: Find all factors

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本文介绍了一种计算任意正整数因子总数的有效算法。通过输入一个正整数N（1<=N<=9999999999999999），该算法能快速输出N的所有因子数量。例如，对于输入12和20，其因子数目分别为6。

Description

Output the number of total factors of an integer.

Input

There are several lines. And each line contains a positive number N (1<=N<=9999999999999999).

Output

Output the number of total factors for each N.

For example,

Input

Output

Because 1, 2, 3, 4, 6, 12 are factors of 12.

1,2,4,5,10,20 are are factors of 20.

Sample Input

12
20

Sample Output

6
6

HINT

#include <stdio.h>
#include <math.h>
 int main()
 {
     long int n, i,sq;
     int fac=0;
     while (scanf("%ld",&n)!=EOF)
     {   sq=sqrt(n);

         for(i=1;i<=sq;i++)
         {
              if(n%i==0)
                fac++;
         }
         fac*=2;
         float sqr=sq;
         if(sqr==sqrt(n))
            fac--;

     printf("%d\n",fac);
     fac=0;
     }
     return 0;
 }