8. In the following vertical calculation, each letter represents a digit from $0 \sim 9$, the same letter represents the same digit, and different letters represent different digits. When the vertical calculation is correct, $A+B+C=$ $\qquad$.
$$
\begin{array}{l}
\begin{array}{llll}
A & B & B & C
\end{array} \\
\begin{array}{lll}
B & B & C
\end{array} \\
\begin{array}{r}
+\quad B \quad B \quad C \\
\hline B A B B
\end{array} \\
\end{array}
$$
15