#include<iostream>
using namespace std;
int main()
{
	long long N,a,x;
	cin>>N;
	for (a=1;a*a<=N;a++)
	x=a*a;
	cout<<x;
	return 0;
	
 } 
### Prompt

Please provide a cpp coded solution 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<iostream>
using namespace std;
int main()
{
	long long N,a,x;
	cin>>N;
	for (a=1;a*a<=N;a++)
	x=a*a;
	cout<<x;
	return 0;
	
 } 
```