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());
}
}
}