#include <cstdio>

using namespace std;

int main(){
	
	double a, b, n;
	double ab;
	int c;
	
	while (scanf("%lf %lf %lf", &a, &b, &n) != EOF){
		c = 0;
		ab = a / b;
		while (ab > 9) ab /= 10;
		for (int i = 0; i < n; i++){
			ab *= 10;
			while (ab > 9) ab -= 10;
			c += ab;
		}
		
		printf("%d\n", c);
	}
}