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 1.8.0) (judge verdict: Accepted)

import java.math.BigDecimal;
import java.util.Scanner;

public class Main {
    public static void main(String... args) {
        Scanner scanner = new Scanner(System.in);

        long A = scanner.nextLong();
        double B = scanner.nextDouble();

        BigDecimal a = new BigDecimal(String.valueOf(A));
        BigDecimal b = new BigDecimal(String.valueOf(B));

        System.out.println(a.multiply(b).longValue());
    }
}