#include <iostream>
#include <math.h>
using namespace std;

int main(){
  int n;cin >> n;
  int s = sqrt(n);
  cout << s*s << endl;
  return 0;
}
### Prompt

Please create a solution in Cpp to 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>
#include <math.h>
using namespace std;

int main(){
  int n;cin >> n;
  int s = sqrt(n);
  cout << s*s << endl;
  return 0;
}
```