PROCEDURE INS(N:INTEGER;VAR L:LL);
  VAR I,J,KEY:INTEGER;
  BEGIN
    FOR J:=2 TO N DO
      BEGIN
      KEY:=L[J];
      I:=J-1;
      WHILE   (I > 0) AND (L[I] > KEY) DO
       BEGIN L[I+1 ]:=L[I];
       I:=I-1;END;
      L[I+1 ]:=KEY
      END
  END;