100 atcoder#ABC141B. [ABC141B] Tap Dance
[ABC141B] Tap Dance
Score: points
Problem Statement
Takahashi will do a tap dance. The dance is described by a string 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.
is said to be easily playable if and only if it satisfies both of the following conditions:
- Every character in an odd position (-st, -rd, -th, ) is
R
,U
, orD
. - Every character in an even position (-nd, -th, -th, ) is
L
,U
, orD
.
Your task is to print Yes
if is easily playable, and No
otherwise.
Constraints
- is a string of length between and (inclusive).
- Each character of is
L
,R
,U
, orD
.
Input
Input is given from Standard Input in the following format:
Output
Print Yes
if is easily playable, and No
otherwise.
RUDLUDR
Yes
Every character in an odd position (-st, -rd, -th, -th) is R
, U
, or D
.
Every character in an even position (-nd, -th, -th) is L
, U
, or D
.
Thus, is easily playable.
DULL
No
The -rd character is not R
, U
, nor D
, so is not easily playable.
UUUUUUUUUUUUUUU
Yes
ULURU
No
RDULULDURURLRDULRLR
Yes