#include <bits/stdc++.h>
using namespace std;

int main() {
	int n;
	cin >> n;
	n = pow((int)floor(sqrt(n)), 2);
	cout << n << endl;
	return 0;
}
### 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 n;
	cin >> n;
	n = pow((int)floor(sqrt(n)), 2);
	cout << n << endl;
	return 0;
}
```