#include<iostream>
using namespace std;

int main(){
  int n, r;
  cin>>n;
  for(int i=1;i*i<=n;i++){
    r = i*i;
  }
  cout<<r<<endl;
  return 0;
}
### Prompt

Generate a cpp solution 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>
using namespace std;

int main(){
  int n, r;
  cin>>n;
  for(int i=1;i*i<=n;i++){
    r = i*i;
  }
  cout<<r<<endl;
  return 0;
}
```