A string is called beautiful if string S = T + T. You're given a string find length of longest beautiful subsequence in given string.

Constraints : 1 <= length(S) <= 100

PS: Ihave no clue except try all numbers with k bits set and like bit-mask check if it's beautiful. Of-course you take k even and start from biggest possible k ie. length(S) - (length(S) & 1). Any hints on this ?