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
public class Main {
	public static void main(String[] args) {
		    java.util.Scanner scanner = new java.util.Scanner(System.in);
                    int n = scanner.nextInt();
                    int root = (int) Math.sqrt((double) n);
                    System.out.println(root * root);
		 } 

}