Imports System

Public Module Module1

    Public Sub Main()

        Dim a,b as single

        Console.write("Entrez la valeur de a :")

        a = console.readline()

        console.write("Entrez la valeur de b :")

        b = console.readline()

        Do 

            If a > b then  a = a - b

            If a < b then b = b - a

        Loop until a= b 

                console.writeline("Le PCGD est : " & a )

    End Sub

End Module