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
#include<stdio.h>
int main(){
int i,n;
  scanf("%d",&n);
  for(i=1;i*i<=n;i++);
  printf("%d",(i-1)*(i-1));
  return 0;

}