#include <iostream>

using namespace std;


int main(int argc, char const* argv[])
{
	double a,b,f;
	int n;

	cin >> a >> b >> n;
	f = a / b;
	f -= int( f );
	int answer = 0;;

	for( int i = 0;i < n;i++ ){
		f *= 10;
		answer += int( f );
		f -= int( f );
	}
	cout << answer << endl;

	return 0;
}