Sub trying(ByVal s As String, ByRef res As String)
    Dim i As Integer
    Dim mass = s.Split(" "c)
    For i = 0 To mass.Length - 1
        If mass(i)(0) = "k"c Then
            res = "Word, begin with k"
            Exit For
        Else
            If mass(i)(mass(i).Length - 1) = "k"c Then
                res = "Word, end with k"
                Exit For
            End If
        End If
    Next
End Sub