10 LET x=10
20 LET y=20
30 DIM a(x)
40 DIM b(y)
50 DIM c(x+y)
60 FOR i=1 TO x
70 LET c(i)=a(i)
80 NEXT i
90 FOR i=1 TO y
100 LET c(x+i)=b(i)
110 NEXT i
120 FOR i=1 TO x+y
130 PRINT c(i);", ";
140 NEXT i