Problem:
Score : 700 points

Problem Statement

Find the smallest possible sum of the digits in the decimal notation of a positive multiple of K.

Constraints

2 \leq K \leq 10^5

K is an integer.

Input

Input is given from Standard Input in the following format:

K

Output

Print the smallest possible sum of the digits in the decimal notation of a positive multiple of K.

Sample Input 1

6

Sample Output 1

3

12=6×2 yields the smallest sum.

Sample Input 2

41

Sample Output 2

5

11111=41×271 yields the smallest sum.

Sample Input 3

79992

Sample Output 3

36

Solution in C (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <stdio.h>
#define aaa 1000000
int sum(long int a)
{
    long int b=0;
    while(a!=0)
    {
        b+=a%10;
        a=a/10;
    }
    return b;
}

int main(void)
{
    long int k;
    scanf("%ld",&k);
    while(k%2==0)k=k/2;
    while(k%5==0)k=k/5;
    int ans=sum(k);
    for(int p=1;p<aaa;p++)
    {
        if(ans>sum(k*p))
          ans=sum(k*p);
    }
    printf("%d",ans);
}