#include <stdio.h> // C++???????????????
#include <string.h> // c++???????????????
#include <math.h> // c++???????????????
#include <stdlib.h>
#include <iostream>
#include <string>
#include <list>
#include <stack>
#include <queue>
#include <map>
#include <algorithm>
using namespace std;

typedef long long int lli;

int main(void) {
	double n;
	int a, b, c;
	int s;

	while (scanf("%d %d %d", &a, &b, &c) != EOF) {
		s = 0;
		n = (double)a / b;
		for (int i = 1,j=10; i <= c; i++,j*=10) {
			s+=((int)(n*j)) % 10;
		}
		printf("%d\n", s);
	}
	return 0;
}