using namespace std;
int main()
{
    double a, b, n;
    cin>>a>>b>>n;
    int t1=pow(10,n);
	int a1=a/b*t1;
	int b1=a1/10;
	b1=b1*10;
	int c=a1-b1;
	cout<<c;
	return 0;
}