Imports System.Text.RegularExpressions

Module Module1

    Sub Main()
        Console.WriteLine("Rectangular single-room carpeting jobs price quote")
        Dim input As String
        Dim roomLength As Integer = findRoomLength()
        Dim roomWidth As Integer = findRoomWidth()
        Dim price As Integer = findPricePerYard()
        Dim squareYardage As Double = findSquareYardage(roomLength, roomWidth)
        Dim materialcost As Double = findMaterialCost(squareYardage, price)
        Dim totalcost As Double
        Do
            Console.WriteLine("Room Length = " & roomLength)
            Console.WriteLine("Room Width = " & roomWidth)
            Console.WriteLine("Price per square yard = $" & price)
            Console.WriteLine("Square Yardage of room = " & squareYardage)
            Console.WriteLine("Material cost = $" & materialcost)
            If ((materialcost) < 800) Then
                Console.WriteLine("Installation cost = $200")
                totalcost = 200 + materialcost
            Else
                Console.WriteLine("Installation cost is free because material cost exceeded $800")
                totalcost = materialcost
            End If
            Console.WriteLine("Total cost = $" & totalcost)
            input = Console.ReadLine()
        Loop
        Console.WriteLine("Quitting now.")
    End Sub
    Private Function findRoomLength() As Integer
        Dim input As String
        Do
            Console.WriteLine("Please enter room length in ft")
            input = Console.ReadLine()
            If (onlyNumbers(input) = False) Then
                Console.WriteLine("Input only numbers")

            End If
        Loop While (onlyNumbers(input) = False And input.Length > 0)
        Return input
    End Function
    Private Function findRoomWidth() As Integer
        Dim input As String
        Do
            Console.WriteLine("Please enter room width in ft")
            input = Console.ReadLine()
            If (onlyNumbers(input) = False) Then
                Console.WriteLine("Input only numbers")

            End If
        Loop While (onlyNumbers(input) = False And input.Length > 0)
        Return input
    End Function
    Private Function findPricePerYard() As Integer
        Dim input As String
        Do
            Console.WriteLine("Please enter the price of the carpeting material on a per-square-yard basis")
            input = Console.ReadLine()
            If (onlyNumbers(input) = False) Then
                Console.WriteLine("Input only numbers")

            End If
        Loop While (onlyNumbers(input) = False And input.Length > 0)
        Return input
    End Function
    Private Function onlyNumbers(ByVal str As String) As Boolean
        Return str.All(AddressOf Char.IsNumber)
    End Function
    Private Function findSquareYardage(ByVal length As Integer, ByVal width As Integer) As Double
        Dim yardLength As Double = length / 3
        Dim yardWidth As Double = width / 3
        Return yardLength * yardWidth
    End Function
    Private Function findMaterialCost(ByVal squareyards As Double, ByVal pricePerYard As Integer) As Double
        Return pricePerYard * squareyards
    End Function
End Module