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 {

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

//    	File file = new File("test.txt");
//    	Scanner sc = new Scanner(file);
    	Scanner sc = new Scanner(System.in);
    	double N = sc.nextDouble();
    	sc.close();
    	for(double i = N; i >= 0; i--){
    		if(Math.sqrt(i) % 1 == 0){
    			System.out.println((int)i);
    			break;
    		}
    	}
    }
}