Procedure isEven(x)
  ProcedureReturn (x & 1) ! 1
EndProcedure

Procedure halveValue(x)
  ProcedureReturn x / 2
EndProcedure

Procedure doubleValue(x)
  ProcedureReturn x << 1
EndProcedure

Procedure EthiopianMultiply(x, y)
  Protected sum, sign = x

  Print("Ethiopian multiplication of " + Str(x) + " and " + Str(y) + " ...")
  Repeat
    If Not isEven(x)
      sum + y
    EndIf
    x = halveValue(x)
    y = doubleValue(y)
  Until x = 0
  If sign < 0 : sum * -1: EndIf

  PrintN(" equals " + Str(sum))
  ProcedureReturn sum
EndProcedure

If OpenConsole()
  EthiopianMultiply(17,34)
  EthiopianMultiply(-17,34)
  EthiopianMultiply(-17,-34)

  Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
  Input()
  CloseConsole()
EndIf