Problem:
Score : 300 points

Problem Statement

Compute A \times B, truncate its fractional part, and print the result as an integer.

Constraints

0 \leq A \leq 10^{15}

0 \leq B < 10

A is an integer.

B is a number with two digits after the decimal point.

Input

Input is given from Standard Input in the following format:

A B

Output

Print the answer as an integer.

Sample Input 1

198 1.10

Sample Output 1

217

We have 198 \times 1.10 = 217.8. After truncating the fractional part, we have the answer: 217.

Sample Input 2

1 0.01

Sample Output 2

0

Sample Input 3

1000000000000000 9.99

Sample Output 3

9990000000000000

Solution in Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

//package bigneer;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.math.BigInteger;

public class Main {

	public static void main(String[] args) throws IOException {
		// TODO Auto-generated method stub

		BufferedReader br =new BufferedReader(new InputStreamReader(System.in));
//		int t=Integer.parseInt(br.readLine());
//		while(t-->0) {
//			int n=Integer.parseInt(br.readLine());
			String q[]=br.readLine().split(" ");
			long a=Long.parseLong(q[0]);
			double b=Double.parseDouble(q[1]);
//			long ans=;
			System.out.println((long)Math.floor((a*b)));
//			long a[]=new long[n];
//			for(int i=0;i<n;i++)
//				a[i]=Long.parseLong(q[i]);
////			long p=1;
//			int b=0;
//			BigInteger p=new BigInteger("1");
//			BigInteger p1=new BigInteger("1000000000000000000");
//			for(int i=0;i<n;i++) {
//				if(a[i]==0) {
//					b=0;
//					p=new BigInteger("0");
//					break;
//				}
//				if(b!=1) {
//				BigInteger w=new BigInteger(Long.toString(a[i]));
//				p=p.multiply(w);
//				if(p.compareTo(p1)==1)
//					{b=1;
////					break;
//					}
//				}
////				if(p>Math.pow(10, 18)||p<0||p<a[i])
////					{b=1;
////				break;}
//					}
////			System.out.println(b);
//			if(b==1)
//				System.out.println(-1);
//			else
//				System.out.println(p);
//			System.out.println();
//		}
	}

}