#include<cstdio>
#include<cmath>
using namespace std;
int n,m;
int main()
{
	scanf("%d",&n);
	m=(int)(sqrt(n));
	printf("%d\n",m*m);
}
### Prompt

Your challenge is to write 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<cstdio>
#include<cmath>
using namespace std;
int n,m;
int main()
{
	scanf("%d",&n);
	m=(int)(sqrt(n));
	printf("%d\n",m*m);
}
```