Count Perfect Squares in an Interval

Given two integers \(c\) and \(d\), count the number of perfect square integers within the interval \([c, d]\) (inclusive). A number \(n\) is a perfect square if there exists an integer \(m\) such that \(n = m^2\). For example, in the interval \([1, 10]\), the perfect squares are 1, 4, and 9, so the answer is 3.

Note that if \(c > d\), then the interval is invalid and the result should be 0. Use the mathematical functions to calculate the square roots and round appropriately with the formulas:

• \(m = \sqrt{n}\)
• \(start = \lceil \sqrt{c} \rceil\)
• \(end = \lfloor \sqrt{d} \rfloor\)

The answer will be \(\max(0, end - start + 1)\) if \(c \leq d\), otherwise 0.

inputFormat

The input consists of two space-separated integers \(c\) and \(d\) on a single line from standard input.

outputFormat

Output a single integer representing the count of perfect square numbers in the interval \([c, d]\).

## sample

1 10

3

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