#include <iostream>
#include <cstdio>
#include <cmath>

using namespace std;

int main() {
	double f, a, b, n;
	while (scanf("%lf %lf %lf", &a, &b, &n) != EOF) {
		int sum = 0;
		f = a / b;
		for (int i = 0; i < n; i++) {
			f -= floor(f);
			f = f * 10;
			sum += floor(f);
		}
		cout << sum << endl;
	}
	return 0;
}