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: Wrong Answer)

using System;
using static AtCoderTemplate.MyLibrary;

namespace AtCoderTemplate
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] AB = Console.ReadLine().Split(' ');
           long a =long.Parse(AB[0]);
           double b =double.Parse(AB[1]);
            long answer = (long)(a * b);

            Console.WriteLine(answer);
        }
    }
    //2回位使ったら追加する
    class MyLibrary
    {
        public static int[] ToIntArray(string[] stringArray)
        {
            int length = stringArray.Length;
            int[] intArray = new int[length];
            for (int i = 0; i < length; i++)
            {
                intArray[i] = int.Parse(stringArray[i]);
            }
            return intArray;
        }
    }
}