import java.util.*;
import java.math.*;
 
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long l = sc.nextLong();
        double d = sc.nextDouble();
        sc.close();
        BigDecimal b1 = BigDecimal.valueOf(l);
        BigDecimal b2 = BigDecimal.valueOf(d);
        BigDecimal b3 = b2.multiply(b1);
        String s = b3.toPlainString();
        char[] c = s.toCharArray();
        StringBuilder sb = new StringBuilder();
        for(int i = 0; i < c.length; i++){
            if(c[i] != '.'){
                sb.append(c[i]);
            }else{
                break;
            }
        }
        System.out.println(sb.toString());
    }
}
/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