import java.math.BigDecimal;
import java.util.*;
public class Main {

    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        while(sc.hasNext()) {
            BigDecimal a = new BigDecimal(Double.toString((double)sc.nextInt()));
            BigDecimal b = new BigDecimal(Double.toString((double)sc.nextInt()));
            int n = sc.nextInt();
            a = a.divide(b,n,BigDecimal.ROUND_FLOOR);
            System.out.println(a.toString());
        }
    }
}