#include <iostream>
#include <vector>
#include <algorithm>

#define INPUT_FROM_FILE (0) 
#if INPUT_FROM_FILE
#include <fstream>
#endif

int main(){
	int a, b, n;
	int result = 0;

#if INPUT_FROM_FILE
	std::ifstream ifs("test.txt");
#endif

#if INPUT_FROM_FILE
	while(ifs >> a >> b >> n){
#else
	while(std::cin >> a >> b >> n){
#endif
		a = 10 * (a % b);

		result = 0;
		for(int i = 0; i < n; i++){
			result += a / b;
			a = 10 * (a % b);
		}
		std::cout << result << std::endl;
	}

	return 0;
}
