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
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long N = sc.nextLong();
    long S[] = new long[50000];
    for(int i=1;i<50000;i++){
      S[i]=(long)i*i;
    }
    int tmp=0;
    while(1==1){
      if(N<S[tmp]){
        System.out.println(S[tmp-1]);
        return;
      }else{
        tmp=tmp+1;
      }
    }
    
  }
  

  
}