interface Shape
  method area() as word
end interface

interface Named
  method label() as char
end interface

interface Scaled
  method scale(f as byte) as word
end interface

interface Boolish
  method ok() as boolean
end interface

interface Left
  method show()
end interface

interface Right
  method show(x as byte)
end interface

class NotIface
end class

class Missing implements Shape
end class

class Hider implements Named
  private method label() as char
    return 'h'
  end method
end class

class WrongParam implements Scaled
  public method scale(f as word) as word
    return f
  end method
end class

class WrongReturn implements Boolish
  public method ok() as word
    return 0
  end method
end class

class Conflict implements Left, Right
  public method show()
  end method
end class

class BadIface implements NotIface
end class

program Main
end program