Imports System
Public Module Module1
Public Sub Main()
Dim a as integer
Dim sum as integer = 0
Console.writeline("Input as many number as you can")
console.writeline("Enter -1 to exit")
Do
sum = sum + a
a = console.readline()
loop until a = -1
'Only can leave the loop when you enter -1'
Console.writeline("The sum of the numbers you have input is" & sum)
End Sub
End Module