On an infinite plane, a robot initially stands at (0, 0) and faces north. The robot can receive one of three instructions: "G": go straight 1 unit; "L": turn 90 degrees to the left; "R": turn 90 degrees to the right. The robot performs the instructions given in order, and repeats them forever. Return true if and only if there exists a circle in the plane such that the robot never leaves the circle.
Input Format
String str
Output Format
boolean value
Constraints
1 <= instructions.length <= 100 instructions[i] is 'G', 'L' or, 'R'.
Notice
NA
Example
Input
GGLLGG
Output
true