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 Kotlin (1.3.71) (judge verdict: Accepted)

import java.util.*

fun str() = readLine()!!
fun int() = str().toInt()
fun long() = str().toLong()

fun read(d:String = " ") = str().split(d)
fun <T> list(d:String = " ",f:String.()->T) = read(d).map {f(it)}
fun list() = list {toInt()}.toIntArray()

fun <T> T.print() = this.also(::println)

fun main() {
	abc000X()
}

fun abc000X() {
	val s = Scanner(System.`in`)
	val a = s.nextLong()
	val b = s.next().replace(".","").toLong()
	println(a*b/100)
}