F. Find Palindromic Subsets - 2018.9 ECNU ICPC/CCPC Trial Round #1 - ECNU Online Judge

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A. Average B. Boxed Lunch C. Cut Tree D. DP Killer E. Endless BFS F. Find Palindromic Subsets G. Gnomes H. Here Comes A Math Problem I. Intersections J. Jim and the Skyscrapers K. KBlack Playing Cards L. Lena Sort M. Memory Penalty