Ears

AtCoder

IDyahoo_procon2019_qual_d

Time2000ms

Memory256MB

Difficulty—

Snuke stands on a number line. He has $L$ ears, and he will walk along the line continuously under the following conditions: * He never visits a point with coordinate less than $0$, or a point with coordinate greater than $L$. * He starts walking at a point with integer coordinate, and also finishes walking at a point with integer coordinate. * He only changes direction at a point with integer coordinate. Each time when Snuke passes a point with coordinate $i-0.5$, where $i$ is an integer, he put a stone in his $i$\-th ear. After Snuke finishes walking, Ringo will repeat the following operations in some order so that, for each $i$, Snuke's $i$\-th ear contains $A_i$ stones: * Put a stone in one of Snuke's ears. * Remove a stone from one of Snuke's ears. Find the minimum number of operations required when Ringo can freely decide how Snuke walks. ## Constraints * $1 \leq L \leq 2\times 10^5$ * $0 \leq A_i \leq 10^9(1\leq i\leq L)$ * All values in input are integers. ## Input Input is given from Standard Input in the following format: $L$ $A_1$ $:$ $A_L$ [samples]

Samples

Input #1

Output #1

1

Assume that Snuke walks as follows:

*   He starts walking at coordinate $3$ and finishes walking at coordinate $4$, visiting coordinates $3,4,3,2,3,4$ in this order.

Then, Snuke's four ears will contain $0,0,2,3$ stones, respectively. Ringo can satisfy the requirement by putting one stone in the first ear.

Input #2

Output #2

Input #3

Output #3

API Response (JSON)

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    "name": "Ears",
    "description": {
      "content": "Snuke stands on a number line. He has $L$ ears, and he will walk along the line continuously under the following conditions: *   He never visits a point with coordinate less than $0$, or a point with",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "yahoo_procon2019_qual_d"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Snuke stands on a number line. He has $L$ ears, and he will walk along the line continuously under the following conditions:\n\n*   He never visits a point with coordinate less than $0$, or a point with...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments