Cancelling an inputbox if blank input or cancel button is pressed

I'm not sure where it went wrong.

Sub numguesser()

Dim ans As Integer
Dim ctr As Integer
Dim guess As Integer
Dim deviation As Integer
Dim msg As String

Randomize
ans = Int(Rnd() * 5000 + 1)

ctr = 0

Do
guess = InputBox("guess the number (1 to 5000)", vbQuestion + vbCancel, "")

If guess = "" Then
Exit Sub
End If

ctr = ctr + 1

If ans > guess Then
    deviation = ans - guess
    Else
    deviation = guess - ans
End If

Select Case deviation
    Case 0
    MsgBox "Congratulations! You have tried " & ctr & " times and get the correct answer of " & ans & ""
    Case 1 To 10
    MsgBox guess & ": very hot"
    Case 11 To 25
    MsgBox guess & ": hot"
    Case 26 To 100
    MsgBox guess & ": cool"
    Case 101 To 500
    MsgBox guess & ": cold"
    Case Is >= 501
    MsgBox guess & ": very cold"
End Select

Loop Until ans = guess


End Sub