#include<iostream>

using namespace std;

int main(){
 long n;
  cin >>n;
  
  long i=n;
  while(i*i>n){
   i--;
  }
   cout << i*i << endl;
}
### Prompt

In CPP, your task is to solve the following problem:

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

### Response

```cpp
#include<iostream>

using namespace std;

int main(){
 long n;
  cin >>n;
  
  long i=n;
  while(i*i>n){
   i--;
  }
   cout << i*i << endl;
}
```