Problem:
Score : 200 points

Problem Statement

Find the largest square number not exceeding N. Here, a square number is an integer that can be represented as the square of an integer.

Constraints

1 \leq N \leq 10^9

N is an integer.

Input

Input is given from Standard Input in the following format:

N

Output

Print the largest square number not exceeding N.

Sample Input 1

10

Sample Output 1

9

10 is not square, but 9 = 3 × 3 is. Thus, we print 9.

Sample Input 2

81

Sample Output 2

81

Sample Input 3

271828182

Sample Output 3

271821169

Solution in Scala (2.11.7) (judge verdict: Wrong Answer)

import scala.math.sqrt

object Main{
  def main(args: Array[String]){
    val input=io.Source.stdin.getLines().mkString("\n")
    println(solve(input).trim())
  }

  def solve(input:String):String={
    val n=input.toInt
    (sqrt(n)+0.5).toInt.toString
  }
}