problem is this.

https://codeforces.com/contest/1003/problem/F

i can't understand why the answer for test case below is 5

3 abcdef abcdef abcdef

my program (and i ) think A abcdef A is optimal so output 10

vovuh's solution output 5.

how 5 is possible? since we should select non-intersecting segments, at least one abcdef should remain and the answer must >=6. need help for this.