Tap Dance

AtCoder

IDabc141_b

Time2000ms

Memory256MB

Difficulty—

Takahashi will do a tap dance. The dance is described by a string $S$ where each character is `L`, `R`, `U`, or `D`. These characters indicate the positions on which Takahashi should step. He will follow these instructions one by one in order, starting with the first character. $S$ is said to be _easily playable_ if and only if it satisfies both of the following conditions: * Every character in an odd position ($1$\-st, $3$\-rd, $5$\-th, $\ldots$) is `R`, `U`, or `D`. * Every character in an even position ($2$\-nd, $4$\-th, $6$\-th, $\ldots$) is `L`, `U`, or `D`. Your task is to print `Yes` if $S$ is easily playable, and `No` otherwise. ## Constraints * $S$ is a string of length between $1$ and $100$ (inclusive). * Each character of $S$ is `L`, `R`, `U`, or `D`. ## Input Input is given from Standard Input in the following format: $S$ [samples]

Samples

Input #1

RUDLUDR

Output #1

Yes

Every character in an odd position ($1$\-st, $3$\-rd, $5$\-th, $7$\-th) is `R`, `U`, or `D`.
Every character in an even position ($2$\-nd, $4$\-th, $6$\-th) is `L`, `U`, or `D`.
Thus, $S$ is easily playable.

Input #2

DULL

Output #2

No

The $3$\-rd character is not `R`, `U`, nor `D`, so $S$ is not easily playable.

Input #3

UUUUUUUUUUUUUUU

Output #3

Yes

Input #4

ULURU

Output #4

No

Input #5

RDULULDURURLRDULRLR

Output #5

Yes

API Response (JSON)

{
  "problem": {
    "name": "Tap Dance",
    "description": {
      "content": "Takahashi will do a tap dance. The dance is described by a string $S$ where each character is `L`, `R`, `U`, or `D`. These characters indicate the positions on which Takahashi should step. He will fol",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "abc141_b"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Takahashi will do a tap dance. The dance is described by a string $S$ where each character is `L`, `R`, `U`, or `D`. These characters indicate the positions on which Takahashi should step. He will fol...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments