import java.util.*;

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

		Scanner sc = new Scanner(System.in);

		Long A = sc.nextLong();
		if(A==0){
			System.out.println("0");
			return;
		}
		String str = sc.next();
		str = str.replace(".", "");
		Long B = Long.valueOf(str);
		A *= B;
      	if(A<100){
         	System.out.println("0");
			return;
        }
      	
		String ans = String.valueOf(A);
		int len = ans.length();
		System.out.println(ans.substring(0, len-2));
		return;
	}
}
/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