A fabrication shop cuts the biggest possible square tile whose area does not exceed a given sheet area A. Because tools only cut integer side lengths, you must find the largest non-negative integer s such that s * s <= A. This is exactly the floor of the square root of A.
Input format
Line 1: a single integer A.
Output format
A single integer: the largest s with s * s <= A.
Constraints
- 0 <= A <= 1000000000000000000