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 (2.13.1) (judge verdict: Accepted)

import io.StdIn.{readInt, readLine}

object Main extends App {
  val n = readInt

  var prev = 0
  var base = 1
  var square = base*base
  while(square <= n) {
    prev = square
    base += 1
    square = base*base
  }

  val result = prev
  println(result)

}