Given a set of DNA string. Find minimum length string S so that, given DNA strings are subsequence of S.

For example, if given set of string is: {CAGT, ATGC, CGTT, ACGT, AATT} then answer is: 8. Because, ACAGTGCT contains all given DNA as subsequence.

Given n such DNA string (n <= 8), each of length atmost 5. Find out the least length.

Sample:
5
AATT
CGTT
CAGT
ACGT
ATGC

Please solve this
regards..........Amran

Output:
8