Challenge: Longest Common Subsequence of Three Sequences

Problem

Longest Common Subsequence of Three Sequences Problem

Compute the longest common subsequence of three sequences.

Input: Three sequences.

Output: Their longest common subsequence.

Given three sequences $A$ = $($$a_{1}$, $a_{2}$,$\ldots$, $a_{n}$$)$, $B$ = $($$b_{1}$, $b_{2},\ldots, b_{m}$$)$, and $C$ = $($$c_{1}$, $c_{2},\ldots, c_{l}$ ...