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.

Examples

Input

10


Output

9


Input

81


Output

81


Input

271828182


Output

271821169
//package Contest077;

import java.io.PrintWriter;
import java.util.Scanner;

public class Main {
    public static void main(String []args)
    {
        Scanner sc = new Scanner(System.in);
        PrintWriter out = new PrintWriter(System.out);
            int N = sc.nextInt();
            int  M = (int)Math.sqrt(new Double(N));
            out.println(M*M);
        out.flush();
    }
}
