func main(first, last) {
    println("Printing the sum of all integers from ", first, " up to, but not including ", last)
    var result = sumRange(first, last)
    println(result)
}

// Calculates the sum of the numbers
// first, first+1, first+2 ... last-2, last-1
func sumRange(first, last) {
    var sumEnd, sumPreFirst
    sumEnd = sumUntil(last)
    sumPreFirst = sumUntil(first)
    return sumEnd - sumPreFirst
}

// Calculates the sum of 1, 2, 3, ..., n-2, n-1
func sumUntil(n) {
    var product = n * (n-1)
    product = product / 2
    return product
}

//TESTCASE: 2 10
//Printing the sum of all integers from 2 up to, but not including 10
//44

//TESTCASE: 6 6
//Printing the sum of all integers from 6 up to, but not including 6
//0