0.4 Dance Moves

Score: 10pts

Time Limit: 2.00 sec

Rishab has to prepare for a dance wherein he has to return to his initial place after all the steps. There are only 4 steps - F(Forward), B(Backward), L(Left), R(Right). Given is a string containing the steps sequence. You have to determine whether after completing all the given steps Rishab will return to his original position or not.

Constraints

\(1 \leq ( \) Length of the string\( ) \leq 10^{4}\)

Input Format

Input will be a single string which contains the sequence of steps

Output Format

Print ‘YES’ if Rishab has returned to his original position, else ‘NO’

Example 1

Input:

LR

Output:

YES

Explanation:

Rishab moves left once, and then right once. All steps have the same magnitude, so Rishab ended up at his initial position. Therefore, we print YES.

LR

Output:

YES

Explanation:

Rishab moves left once, and then right once. All steps have the same magnitude, so Rishab ended up at his initial position. Therefore, we print YES.

Example 2

Input:

FFB

Output:

NO

Explanation:

Rishab moves forward twice and backward once. He ends up one "step" in front of the origin. We print NO because it is not at his initial position.

FFB

Output:

NO

Explanation:

Rishab moves forward twice and backward once. He ends up one "step" in front of the origin. We print NO because it is not at his initial position.