Secret Passage

AtCoder

IDagc046_d

Time2000ms

Memory256MB

Difficulty—

Given is a string $S$ consisting of `0` and `1`. Find the number of strings, modulo $998244353$, that can result from applying the following operation on $S$ zero or more times: * Remove the two characters at the beginning of $S$, erase one of them, and reinsert the other somewhere in $S$. This operation can be applied only when $S$ has two or more characters. ## Constraints * $1 \leq |S| \leq 300$ * $S$ consists of `0` and `1`. ## Input Input is given from Standard Input in the following format: $S$ [samples]

Samples

Input #1

Output #1

8

Eight strings, `0001`, `001`, `010`, `00`, `01`, `10`, `0`, and `1`, can result.

Input #2

Output #2

Input #3

11101111011111000000000110000001111100011111000000001111111110000000111111111

Output #3

697354558

API Response (JSON)

{
  "problem": {
    "name": "Secret Passage",
    "description": {
      "content": "Given is a string $S$ consisting of `0` and `1`. Find the number of strings, modulo $998244353$, that can result from applying the following operation on $S$ zero or more times: *   Remove the two ch",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "agc046_d"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Given is a string $S$ consisting of `0` and `1`. Find the number of strings, modulo $998244353$, that can result from applying the following operation on $S$ zero or more times:\n\n*   Remove the two ch...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments