#include<bits/stdc++.h>
using namespace std;

int main(){
	int n,s=1;
	double a,b,c;
	cin>>a>>b>>n;
	c=a/b;
	for(int i=1;i<=n;i++){
		s*=10;
	}
	int t=c*s;
	cout<<t%10;
	return 0;
}

90分,99鞋子8,555