{"problem":{"name":"07. Labyrinth-7","description":{"content":"See the problem statement here: [http://codeforces.com/contest/921/problem/01](//codeforces.com/contest/921/problem/01).","description_type":"Markdown"},"platform":"Codeforces","limit":{"time_limit":8000,"memory_limit":524288},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"CF92107"},"statements":[{"statement_type":"Markdown","content":"See the problem statement here: [http://codeforces.com/contest/921/problem/01](//codeforces.com/contest/921/problem/01).\n\n[samples]","is_translate":false,"language":"English"},{"statement_type":"Markdown","content":"请参见此处的问题描述：http://codeforces.com/contest/921/problem/01.\n\n[samples]","is_translate":true,"language":"Chinese"},{"statement_type":"Markdown","content":"**Definitions**  \nLet $ n \\in \\mathbb{Z} $ be the number of elements in 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 sequence has an alternating sum of zero, i.e.,  \n$$\n\\sum_{i=1}^{m} (-1)^{i-1} b_i = 0\n$$  \nwhere $ B = (b_1, b_2, \\dots, b_m) $ is the subsequence of $ A $ after removals, with $ m \\geq 1 $, and the signs alternate starting with $ + $.","is_translate":false,"language":"Formal"}],"meta":{"iden":"CF92107","tags":[],"sample_group":[],"created_at":"2026-03-03 11:00:39"}}