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 Kotlin (1.0.0) (judge verdict: Accepted)

fun main(args:Array<String>){
  var ans = 1;
  val n = readLine()?.toInt()!!
  for(i in 1..n){
    if(i*i>n) break;
    ans = i*i
  }
  println(ans)
}