#include <stdio.h>

int main(void) {
  int i, n;
  scanf("%d", &n);
  for(i = 1; i * i <= n; ++i);
  i--;
  printf("%d", i * i);
  return 0;
}
### Prompt

In cpp, your task is to solve 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 <stdio.h>

int main(void) {
  int i, n;
  scanf("%d", &n);
  for(i = 1; i * i <= n; ++i);
  i--;
  printf("%d", i * i);
  return 0;
}
```