CodeForces - 900B 思维

You have a fraction . You need to find the first occurrence of digit c into decimal notation of the fraction after decimal point.

Input

The first contains three single positive integers a, b, c (1 ≤ a < b ≤ 10⁵, 0 ≤ c ≤ 9).

Output

Print position of the first occurrence of digit c into the fraction. Positions are numbered from 1 after decimal point. It there is no such position, print -1.

Examples

Input

1 2 0

Output

2

Input

2 3 7

Output

-1

Note

The fraction in the first example has the following decimal notation: . The first zero stands on second position.

The fraction in the second example has the following decimal notation: . There is no digit 7 in decimal notation of the fraction.

题意：求c出现在a/b的小数点后的多少位，不存在输出-1；

#include<bits\stdc++.h>
using namespace std;
const int len=1e2+3;
#define ll long long
int main()
{
	int a,b,c;
	int w=0;
	cin>>a>>b>>c;
	a=a%b;//去掉整数位，保证b>a; 
	int t=1e7;//保证不超时，越大越好
	int sum=0;//计数 
	while(t--)
	{
		sum++;
		a=a*10;
		int ans=a/b%10;//a的第一位小数为a*10/b 
		//ans为a/b的sum位小数 
		if(ans==c)
		{
			w=1;
			break;
		}
		a=a%b;//去掉整数部分 
	}
	if(w)cout<<sum<<endl;
	else puts("-1"); 
}