$6\mathrm{.}8\mathrm{.}2$: Modifying ArrayList using add$()$ and remove$().$

Modify the existing ArrayLists's contents, by erasing the second element, then inserting $100$ and $102$ in the shown locations. Use ArrayList's remove$()$ and add$()$ only. Sample output of below program with input $101200103$:

$100101102103$