|Codeforces Round #201 (Div. 1)|
In mathematics, a subsequence is a sequence that can be derived from another sequence by deleting some elements without changing the order of the remaining elements. For example, the sequence BDF is a subsequence of ABCDEF. A substring of a string is a continuous subsequence of the string. For example, BCD is a substring of ABCDEF.
You are given two strings s 1, s 2 and another string called virus. Your task is to find the longest common subsequence of s 1 and s 2, such that it doesn't contain virus as a substring.
The input contains three strings in three separate lines: s 1, s 2 and virus (1 ≤ |s 1|, |s 2|, |virus| ≤ 100). Each string consists only of uppercase English letters.
Output the longest common subsequence of s 1 and s 2 without virus as a substring. If there are multiple answers, any of them will be accepted.
If there is no valid common subsequence, output 0.