Function findInverse(m As Integer, modulus As Integer) As Variant
    Dim i As Integer
    Dim xOne As Integer
    Dim xTwo As Integer
    Dim temp As Integer
    Dim remainder As Integer
    Dim divisor As Integer
    Dim dividend As Integer
    Dim allQuotients() As Integer
    
    '-----Calculate the GCD and quotients
    'The expression a = b * q + r will become
    'dividand = divisor * q + remainder
    
    dividend = m
    divisor = modulus

    'need to swap for this one because the number of quotients matters;
    'if a < b then we get a large initial quotient as an extra step
    If modulus > m Then
        dividend = modulus
        divisor = m
    End If
    
    ReDim allQuotients(0 To (dividend - 1)) 'resize the array
    remainder = dividend 'arbitrary initialization
    i = 0

    '---Loop go get quotients
    Do While remainder > 1
        'calculate new q and r
        remainder = dividend Mod divisor
        allQuotients(i) = dividend \ divisor
        i = i + 1
        'Shift over b and r to replace a and b
        dividend = divisor
        divisor = remainder
    Loop
    
    '-----If the GCD is not 1, then the inverse is not defined.
    If Not (remainder = 1) Then
        findInverse = "No Inverse"
        Exit Function
    End If
    
    ReDim Preserve allQuotients(0 To (i - 1)) 'cut off unused elements
    
    '-----Calculate the Inverse using the quotients obtained
    'Extended euclidian algorithm with block method
    'Uses only the second row.
    '    |(quotients q1, q2, ...)
    '----------
    '0 1 | 0 - 1 * q1 | 1 - (0 - 1 * q1) * q2 |...
    
    xOne = 0
    xTwo = 1
    temp = 0 'arbitrary initialisation
    
    '---Loop for the calculation of the inverse via block
    For i = 0 To UBound(allQuotients)
        temp = xOne - (xTwo * allQuotients(i))
        xOne = xTwo
        xTwo = temp
    Next i
    
    '-----Make sure the inverse is between zero and the modulus
    While xTwo < 0
        xTwo = xTwo + modulus
    Wend
    
    findInverse = xTwo 'return!
End Function