AtCoder Beginner Contest 141
B
Tap Dance
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原题
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翻译中…

Problem Statement

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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.

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$S$ is said to be easily playable if and only if it satisfies both of the following conditions:

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  • 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.
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Your task is to print Yes if $S$ is easily playable, and No otherwise.

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Constraints

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  • $S$ is a string of length between $1$ and $100$ (inclusive).
  • Each character of $S$ is L, R, U, or D.
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Input

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Input is given from Standard Input in the following format:

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S

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Output

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Print Yes if $S$ is easily playable, and No otherwise.

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样例

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
题目信息
题号
abc141_b
时间限制
2 s
内存限制
1024 MB

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