Sub lab()
Dim i As Integer
    For i = 1 To 5
    Worksheets("Sheet1").Range("A" & i).Value = InputBox("enter last name student - " & i)
    Worksheets("Sheet2").Range("A" & i).Value = InputBox("enter first name student - " & i)
    Next i

    For i = 2 To 6
    Worksheets("Sheet3").Range("B" & i).Value = Worksheets("Sheet1").Range("A" & i - 1).Value & " " & Worksheets("Sheet2").Range("A" & i - 1).Value
    Worksheets("Sheet3").Range("A" & i).Value = i - 1
    Next i
End Sub