Define.i n=0, sum=0
Define.f i

If OpenConsole()
  Repeat
    Print("Enter integral rainfall (99999 to quit): ")
    i=ValF(Input())
    If i=99999
      Break
    ElseIf i<0 Or i<>Int(i)
      PrintN("Must be an integer no less than 0, try again.")
    Else
      n+1
      sum+i
      PrintN("  The current average rainfall is "+StrF(sum/n,5))
    EndIf
  ForEver
EndIf