ARCCARC
1

53

Below are some examples of the initial string $S$ from which we can get the string $T$ = `ARCCARC` with at most $1$ operation. - $S$ = `ARCCARC`: we can choose to do nothing to get `ARCCARC`. - $S$ = `CRACARC`: we can choose the $1$-st, $2$-nd, $3$-rd characters and overwrite them with `ARC` to get `ARCCARC`. - $S$ = `ARCCCCC`: we can choose the $5$-th, $6$-th, $7$-th characters and overwrite them with `ARC` to get `ARCCARC`. There are many other strings that could be $S$, for a total of $53$.

ARARCRCA
5

2187

If the intial string $S$ is `AAAAAAAA`, one way to get $T$ = `ARARCRCA` with at most $5$ operations is as follows. - Step $1$: choose the $3$-rd, $4$-th, $5$-th characters and overwrite them with `ARC` to get the string `AAARCAAA`. - Step $2$: choose the $5$-th, $6$-th, $7$-th characters and overwrite them with `ARC` to get the string `AAARARCA`. - Step $3$: choose the $1$-st, $2$-nd, $3$-rd characters and overwrite them with `ARC` to get the string `ARCRARCA`. - Step $4$: choose the $3$-rd, $4$-th, $5$-th characters and overwrite them with `ARC` to get the string `ARARCRCA`. There are many other strings that could be $S$, for a total of $2187$.

AARCRRARCC
0

1

We can get $T$ = `AARCRRARCC` with $0$ operations in only one case in which $S = T$ from the beginning, or $S$ = `AARCRRARCC`.

AAAAARRRRRCCCCC
131

1

In this case, there is just one string that could be $S$: `AAAAARRRRRCCCCC`.

CAARCACRAAARARARCRCRARCARARCRRARC
9

797833187

There are $320236026147$ strings that could be $S$, so print this count modulo $998244353$, which is $797833187$.