import java.util.*;

public class Exercise49{
  public static void main (String[] args){

    Scanner sc = new Scanner(System.in);

    double v = sc.nextDouble() + 0.00001;
    int t = sc.nextInt();

    String numStr = String.valueOf(v);
    int vd = Integer.parseInt(numStr.substring(2, 6));

    System.out.println(vd * t / 10000);
  }
}