How to stop the for loop?

hi all, i am facing another problem here.

i want to stop a for loop.

i attach my excile file at here.
it is call as parent if the column "a" is blank n hv alphabet.
if the column "a" is not blank n hv numberic it is call as child.
i want to delete the child if the parent come out a word "mount"


here are my code

Sub aa()
  
 r = ActiveSheet.UsedRange.Rows.Count
 For i = 1 To r - 1
    If InStr(3, Cells(i, 3).Value, "MOUNT") > 0 Then
    z = i + 1
 
    For z = 1 To r - 1
      If Cells(z, "a").Value <> "" Then
      Rows(z).Select
      Selection.Delete Shift:=xlUp
       'ElseIf Cells(z, "a").Value = "" Then
       'stop this for loop and go to find another parent whether hv mount -- this part how to write --
    End If
    
      Next
      
    End If
  Next i
End Sub