Option Strict On

Module Module1
    Const n As Int32 = 3
    Dim i As Int32
    Dim c(n - 1) As String

    Sub Main()
        For i = 0 To n - 1
            c(i) = Console.ReadLine()
        Next

        For i = 0 To n - 1
            Console.Write(c(i)(i))
        Next

        Console.WriteLine()
    End Sub

End Module