Summing Integers in a Range

Given two integers \(a\) and \(b\), compute the sum of all integers between them (inclusive). If \(a \gt b\), swap them so that the sum is computed from the smaller number to the larger number.

You can use the formula for the sum of an arithmetic series:

\( S = n \times \frac{(first + last)}{2} \)

where \( n = (last - first + 1) \).

For example:

• If the input is 1 5, the output should be 15.
• If the input is 10 7, the output should be 34 (because the sum is computed from 7 to 10).

inputFormat

The input is read from standard input and consists of a single line containing two space-separated integers \(a\) and \(b\).

outputFormat

The output should be a single integer, representing the sum of all integers between \(a\) and \(b\) (inclusive), computed using the arithmetic series formula.

1 5

15