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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)


import java.util.Scanner;

public class Main {

	static Scanner sc = new Scanner(System.in);

	static int res = 0;

	public static void main(String[] args) throws Exception {


		int k=sc.nextInt();
		

		System.out.println(helper(k));

	}

	private static int helper(int k) {
		// TODO Auto-generated method stub
		int n=(int) Math.sqrt(k);
		return n*n;
	}

}