10 DATA "a","bb","ccc","ddd","ee","f","ggg","~"
20 RESTORE
30 READ TEST$
40 IF TEST$ = "~" THEN GOTO 80
50 IF LEN(TEST$) > LEN(TEST1$) THEN LET TEST1$ = TEST$ : LET TEST2$ = TEST1$ + CHR$(10) : GOTO 30
60 IF LEN(TEST$) = LEN(TEST1$) THEN LET TEST2$ = TEST2$ + TEST$ + CHR$(10)
70 GOTO 30
80 PRINT TEST2$
90 END