REM CONSTANTS
 100 TWO% =  INT ( VAL ("2"))
 REM NOT IS A "LOGICAL" OPERATOR, A NON-ARITHMETIC OPERATOR
 110 UN% =  NOT FALSE%
 REM MSG$ = "PRESS CTRL+C THEN RETURN FOR END-OF-TEXT"
 REM BUT NEED THE HIGH BIT SET, SO ASSIGN MSG$ THE TEDIOUS WAY
 111 R$ =  CHR$ ( INT ( VAL ("210")))
 112 E$ =  CHR$ ( INT ( VAL ("197")))
 113 S$ =  CHR$ ( INT ( VAL ("211")))
 114 SPACE$ =  CHR$ ( INT ( VAL ("160")))
 115 C$ =  CHR$ ( INT ( VAL ("195")))
 116 T$ =  CHR$ ( INT ( VAL ("212")))
 117 N$ =  CHR$ ( INT ( VAL ("206")))
 118 F$ =  CHR$ ( INT ( VAL ("198")))
 119 HYPHEN$ =  CHR$ ( INT ( VAL ("173")))
 120 MSG$ =  CHR$ ( INT ( VAL ("208"))) + R$ + E$ + S$ + S$ + SP$
 121 MSG$ = MSG$ + C$ + T$ + R$ +  CHR$ ( INT ( VAL ("204"))) +  CHR$ ( INT ( VAL ("171"))) + C$ + SP$
 122 MSG$ = MSG$ + T$ +  CHR$ ( INT ( VAL ("200"))) + E$ + N$ + SP$
 123 MSG$ = MSG$ + R$ + E$ + T$ +  CHR$ ( INT ( VAL ("213"))) + R$ + N$ + SP$
 124 MSG$ = MSG$ + F$ +  CHR$ ( INT ( VAL ("207"))) + R$ + SP$
 125 MSG$ = MSG$ + E$ + N$ +  CHR$ ( INT ( VAL ("196"))) + HY$ +  CHR$ ( INT ( VAL ("207"))) + F$ + HY$
 126 MSG$ = MSG$ + T$ + E$ +  CHR$ ( INT ( VAL ("216"))) + T$
 REM OUTPUT THE MESSAGE TO THE TOP OF THE TEXT SCREEN
 130 IT$ = "12345678901234567890123"
 140  TEXT : HOME : VTAB TWO%: POKE 34,UN%
 REM + IS A "STRING" OPERATOR, A NON-ARITHMETIC OPERATOR WHEN USED WITH STRINGS FOR CONCATENATION
 150 IT$ = IT$ + "."
 160 P% =  INT ( VAL ("10" +  STR$ ( LEN (IT$))))
 170  POKE P%, INT ( ASC ( LEFT$ (MSG$,UN%)))
 180 MSG$ =  MID$ (MSG$,TWO%)
 190  IF  LEN (MSG$) GOTO 150
 REM READ STDIN
 200  ONERR  GOTO 500"END OF DATA?
 210  INPUT "";STD$
 220 L% =  INT ( LEN (STD$))
 230  IF  NOT L% GOTO 210"READ NEXT LINE IF EMPTY
 250 IT$ = BIGGEST$
 260 COMPARE$ = STD$
 REM COMPARE WITH LONGEST STRING
 270  IF  INT ( LEN (COMPARE$)) GOTO 300"DECREMENT
 280  IF  INT ( LEN (IT$)) GOTO 210"READ NEXT LINE IF LESS THAN LONGEST STRING
 REM EQUAL TO LONGEST STRING
 290 RESULT$ = RESULT$ +  CHR$ (INT ( VAL ("13"))) + STD$: GOTO 210"READ NEXT LINE
 REM REMOVE A CHARACTER FROM BOTH IF THEY STILL HAVE LENGTH
 300  IF  INT ( LEN (IT$)) THEN IT$ =  MID$ (IT$,TWO%):COMPARE$ =  MID$ (COMPARE$,TWO%): GOTO 270"COMPARE AGAIN
 REM GREATER THAN LONGEST STRING
 310 BIGGEST$ = STD$
 320 RESULT$ = BIGGEST$
 330  GOTO 210"READ NEXT LINE
 REM CATCH ERROR
 500  POKE  INT ( VAL ("216")),ZERO%
 510 E% =  INT ( PEEK ( INT ( VAL ("222"))))
 REM CLEAR THE MESSAGE FROM THE TEXT SCREEN
 520 V% =  INT ( PEEK ( INT ( VAL ("37"))))
 530  TEXT : VTAB UN%: CALL  INT ( VAL ("-868"))
 540  VTAB V%: CALL INT ( VAL ("-912"))
 REM ERROR CODE 255
 550 IT$ = "12345678901234567"
 560 IT$ = IT$ + IT$ + IT$
 570 IT$ = IT$ + IT$ + IT$ + IT$ + IT$
 580 COMPARE$ =  MID$ (IT$,UN%,E%)
 REM COMPARE ERROR CODE WITH 255
 590  IF  INT ( LEN (COMPARE$)) GOTO 610"DECREMENT
 600  RESUME
 REM REMOVE A CHARACTER FROM THE ITERATOR
 610 IT$ =  MID$ (IT$,TWO%)
 REM DONE? IF NOT DONE REMOVE A CHARACTER FROM THE ERROR CODE
 620  IF  INT ( LEN (IT$)) THEN COMPARE$ =  MID$ (COMPARE$,TWO%): GOTO 590"COMPARE AGAIN
 630  PRINT RESULT$