10 LET A$="abcdefghijklmnopqrstuvwxyz": LET la=LEN A$
20 LET n=10: LET m=7
30 PRINT A$(n TO n+m-1)
40 PRINT A$(n TO )
50 PRINT A$( TO la-1)
60 FOR i=1 TO la
70 IF A$(i)="g" THEN PRINT A$(i TO i+m-1): LET i=la
80 NEXT i
90 LET B$="ijk": LET lb=LEN b$
100 FOR i=1 TO la-lb+1
110 IF A$(i TO i+lb-1)=B$ THEN PRINT A$(i TO i+m-1): LET i=la-lb+1
120 NEXT i