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 C# (.NET Core 3.1.201) (judge verdict: Accepted)

using System;

namespace AtCoder{
    public static class AtCoder{
        public static void Main(){
            var input = Console.ReadLine().Split(' ');
            long a = long.Parse(input[0]);
            decimal b = decimal.Parse(input[1]);

            decimal ans = a * b;
            ans = Math.Truncate(ans);
            Console.WriteLine(ans);
        }
    }
}