Count 1's

AtCoder

IDarc137_b

Time2000ms

Memory256MB

Difficulty—

You are given an integer sequence of length $N$ consisting of $0$ and $1$: $A=(A_1,A_2,\cdots,A_N)$. You will do the operation below exactly once. * Choose a **contiguous** subsequence of $A$ and flip the elements in it: convert $0$ to $1$ and vice versa. Here, you may choose an empty subsequence, in which case the elements of $A$ do not change. Your score will be the number of $1$'s in $A$. How many values are there that your score can take? ## Constraints * $1 \leq N \leq 3 \times 10^5$ * $0 \leq A_i \leq 1$ * All values in input are integers. ## Input Input is given from Standard Input in the following format: $N$ $A_1$ $A_2$ $\cdots$ $A_N$ [samples]

Samples

Input #1

4
0 1 1 0

Output #1

4

There are four possible values for your score: $0, 1, 2, 3$. For example, if you flip the $2$\-nd through $4$\-th elements of $A$, you will get $A=(0,0,0,1)$, for a score of $1$.

Input #2

5
0 0 0 0 0

Output #2

Input #3

6
0 1 0 1 0 1

Output #3

API Response (JSON)

{
  "problem": {
    "name": "Count 1's",
    "description": {
      "content": "You are given an integer sequence of length $N$ consisting of $0$ and $1$: $A=(A_1,A_2,\\cdots,A_N)$. You will do the operation below exactly once. *   Choose a **contiguous** subsequence of $A$ and f",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "arc137_b"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "You are given an integer sequence of length $N$ consisting of $0$ and $1$: $A=(A_1,A_2,\\cdots,A_N)$.\nYou will do the operation below exactly once.\n\n*   Choose a **contiguous** subsequence of $A$ and f...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments