#include <iostream>
int n,i;
int main() {
	std::cin>>n;
	for(i=1; i*i<=n; i++);
	std::cout<<(i-1)*(i-1);
}
### 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 <iostream>
int n,i;
int main() {
	std::cin>>n;
	for(i=1; i*i<=n; i++);
	std::cout<<(i-1)*(i-1);
}
```