#include <iostream>
#include<math.h>

int main()
{  long long N,n;
   std::cin>>N;
   n=int(sqrtl(N));
   std::cout<<n*n;
  return 0;
}
### Prompt

Construct a CPP code solution to the problem outlined:

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>

int main()
{  long long N,n;
   std::cin>>N;
   n=int(sqrtl(N));
   std::cout<<n*n;
  return 0;
}
```