Sqrt(x)

Given a non-negative integer x, return the square root of x rounded down to the nearest integer. The returned integer should be non-negative as well.

You must not use any built-in exponent function or operator (e.g., Math.sqrt or **).

Examples

Example 1:

Input: x = 4

Output: 2

Explanation: The square root of 4 is 2.

Example 2:

Input: x = 8

Output: 2

Explanation: The square root of 8 is 2.828..., which rounded down is 2.

Constraints

• 0 <= x <= 2^31 - 1