#include <iostream>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <bitset>
#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cmath>

#define X first
#define Y second
using namespace std;

int main(){
	double a, b;
	int n;
	while(cin >> a >> b >> n){
		if(cin.eof()) break;
		double div = a/b;
		while(div>=1) div--;
		int sum = 0;
		for(int i = 0; i < n; i++){
			int tmp = div*10;
			sum += tmp;
			div = (div*10)-tmp;
		}
		cout << sum << endl;
	}
	return 0;
}