Biologists finally invent techniques of repairing DNA that contains segments causing kinds of inherited diseases. For the sake of simplicity, a DNA is represented as a string containing characters 'A', 'G' , 'C' and 'T'. The repairing techniques are simply to change some characters to eliminate all segments causing diseases. For example, we can repair a DNA "AAGCAG" to "AGGCAC" to eliminate the initial causing disease segments "AAG", "AGC" and "CAG" by changing two characters. Note that the repaired DNA can still contain only characters 'A', 'G', 'C' and 'T'.
You are to help the biologists to repair a DNA by changing least number of characters.
The last test case is followed by a line containing one zeros.
2 AAA AAG AAAG 2 A TG TGAATG 4 A G C T AGT 0
Case 1: 1 Case 2: 4 Case 3: -1
AC Rate 75%
Date 03/06/2019 16:29:19