#include<bits/stdc++.h>
using namespace std;
int main(){
  int x,z;
  cin>>x;
  for(z=1;z*z<=x;z++){}
  cout<<(z-1)*(z-1)<<endl;
}
### Prompt

Develop a solution in Cpp to the problem described below:

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<bits/stdc++.h>
using namespace std;
int main(){
  int x,z;
  cin>>x;
  for(z=1;z*z<=x;z++){}
  cout<<(z-1)*(z-1)<<endl;
}
```