10 DATA 0
20 DATA 1,"ABC"
30 DATA 2,"ABC","DEF"
40 DATA 4,"ABC","DEF","G","H"
50 FOR n=10 TO 40 STEP 10
60 RESTORE n: GO SUB 1000
70 NEXT n
80 STOP
1000 REM quibble
1010 LET s$=""
1020 READ j
1030 IF j=0 THEN GO TO 1100
1040 FOR i=1 TO j
1050 READ a$
1060 LET s$=s$+a$
1070 IF (i+1)=j THEN LET s$=s$+" and ": GO TO 1090
1080 IF (i+1)<j THEN LET s$=s$+", "
1090 NEXT i
1100 PRINT "{";s$;"}"
1110 RETURN