import java.util.Scanner;

/*

*/

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

        Scanner sc = new Scanner(System.in);
        long a = sc.nextLong();
        double b = sc.nextDouble();

        long std = a;
        if (a >= 100) {
        	a = a/100;
        }
        double ans = Math.floor(a * b);
        if (std >= 100) {
        	ans = ans*100;
        }
        System.out.println((long)ans);

    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz