#include<iostream>
using namespace std;
int u10(int n)
{
	int m = 1;
	for (int i = 0; i < n; i++)
	{
		m *= 10;
	}
	return m;
}
int main()
{
	int a = 0;
    int b = 0;
	int n = 0;
	cin >> a >> b >> n;
	double x = (double)a / b;
	x *= u10(n);
	cout << (int)x - (int)x / 10 * 10;
}