{"problem":{"name":"Sequence","description":{"content":"You are given an integer sequence of length $N$. The $i$\\-th term in the sequence is $a_i$. In one operation, you can select a term and either increment or decrement it by one. At least how many opera","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"arc072_a"},"statements":[{"statement_type":"Markdown","content":"You are given an integer sequence of length $N$. The $i$\\-th term in the sequence is $a_i$. In one operation, you can select a term and either increment or decrement it by one.\nAt least how many operations are necessary to satisfy the following conditions?\n\n*   For every $i$ $(1≤i≤n)$, the sum of the terms from the $1$\\-st through $i$\\-th term is not zero.\n*   For every $i$ $(1≤i≤n-1)$, the sign of the sum of the terms from the $1$\\-st through $i$\\-th term, is different from the sign of the sum of the terms from the $1$\\-st through $(i+1)$\\-th term.\n\n## Constraints\n\n*   $2 ≤ n ≤ 10^5$\n*   $|a_i| ≤ 10^9$\n*   Each $a_i$ is an integer.\n\n## Input\n\nInput is given from Standard Input in the following format:\n\n$n$\n$a_1$ $a_2$ $...$ $a_n$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"arc072_a","tags":[],"sample_group":[["4\n1 -3 1 0","4\n\nFor example, the given sequence can be transformed into $1, -2, 2, -2$ by four operations. The sums of the first one, two, three and four terms are $1, -1, 1$ and $-1$, respectively, which satisfy the conditions."],["5\n3 -6 4 -5 7","0\n\nThe given sequence already satisfies the conditions."],["6\n-1 4 3 2 -5 4","8"]],"created_at":"2026-03-03 11:01:13"}}