#include <iostream>
#include <string>
#include <sstream>

using namespace std;

int main()
{
	string str = "";

	while (getline (cin, str ) ){
		int a,b,n;
		stringstream ss(str);

		ss >> a >> b >> n;
		if (a % b == 0){
			cout << '0' << endl;
			continue;
		} // end if

		while (a > b){
			a -= b;
		} // end if	

		int sum = 0;
		
		for (int i = 0; i < n; ++i){
			int c = (10*a)/b;
			int d = (10*a % b);
			a = d;
			sum += c;
		} // end for
		cout << sum << endl;

	} // end loop
		
	return 0;
}