#include <iostream>
using namespace std;

int main() {
	int a, b, n;
	while(cin >> a >> b >> n) {
		if(a % b == 0) {
			cout << "0" << endl;
			continue;
		}

		if(a > b) a -= b;
		int s = 0;
		for(int i = 0; i < n; ++i) {
			s += 10 * a / b;
			a = 10 * a % b;
		}
		cout << s << endl;
	}
}