{"raw_statement":[{"iden":"statement","content":"See the problem statement here: [http://codeforces.com/contest/921/problem/01](//codeforces.com/contest/921/problem/01)."}],"translated_statement":[{"iden":"statement","content":"请参见此处的问题陈述：http://codeforces.com/contest/921/problem/01。\n\n"}],"sample_group":[],"show_order":[],"formal_statement":"**Definitions**  \nLet $ n \\in \\mathbb{Z}^+ $ be the length of the sequence.  \nLet $ A = (a_1, a_2, \\dots, a_n) $ be a sequence of positive integers.\n\n**Constraints**  \n1. $ 1 \\leq n \\leq 100 $  \n2. $ 1 \\leq a_i \\leq 100 $ for all $ i \\in \\{1, \\dots, n\\} $\n\n**Objective**  \nFind the minimum number of elements to remove from $ A $ such that the remaining subsequence has an alternating sum of zero, i.e., there exists a subsequence $ B = (b_1, b_2, \\dots, b_m) $ with $ m \\geq 1 $, where:  \n$$\n\\sum_{j=1}^{m} (-1)^{j-1} b_j = 0\n$$  \nand $ m $ is maximized (equivalently, removals are minimized).","simple_statement":null,"has_page_source":false}