#include<iostream>
#include<cmath>
using namespace std;
int main(){
    int n;
    cin>>n;
    int k=sqrt(n);
    cout<<k*k;
}
### 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<cmath>
using namespace std;
int main(){
    int n;
    cin>>n;
    int k=sqrt(n);
    cout<<k*k;
}
```