with Text_io;

procedure PRIMES is -- outputs prime numbers between 1 and 100
  -- A prime is a number P that can not be divided evenly
  -- by a number between 2 and P-1.
  -- 1 is considered to prime.
  N:constant integer:=100;-- Largest number to be considered

  package INT_IO is new Text_IO.Integer_io(integer);
  
begin

  for P in 1..N loop  -- For each possible prime in turn...

   declare
	COMPOSITE:exception; -- assume prime, exception COMPOSITE if not 
   begin

    DIVISIONS:
    for D in 2..P-1 loop  -- See if D divides P

      if P mod D = 0 then -- P is divisible by D
        raise COMPOSITE;
      end if;

    end loop DIVISIONS;

    INT_IO.put(P);
  exception
	when COMPOSITE=>null;
	when others=>raise;
  end;

  end loop;

end PRIMES;