program (reserved word)

   program          ... ; { Program heading }
   uses             ... ; { Uses clause }
   label            ... ; { Labels }
   const            ... ; { Constants }
   type             ... ; { Types }
   var              ... ; { Variables}
   procedure        ... ; { Procedures }
   function         ... ; { Functions }
   begin
      statement;    { Statements }
       ...
   end.

  - The program heading specifies the program's name and parameters; it is
    purely informative and has no meaning to the program itself.

  - The uses clause lists the units used by the program.

  - The label, constant, variable, procedure, and function declaration parts
    can be listed in any order, and repeated any number of times.

  - The statement part specifies the statements to be executed when the
    program runs.