Question 20 (Advanced problem) It is required to write a function to check if a robot have been instructed to move in a loop (starts and stops at the same location). The robot is positioned on a grid, in the location (0,0) and facing North. The robot can receive a sequence of instructions, where: F: move forward L: rotate 90deg on the spot R: rotate -90deg on the spot For example: FFLLFF, in this sequence the robot moves from (0,0) to (0,1), then (0,2), turns 180 degrees, and then returns to (0,1) then (0,0). Write a function that accept a string that represent sequence of moves (path) and return True if this sequence represent a loop, False otherwise. The function has the following definition: def is_loop (path): BE IT IT IT Input: path as string represent the robot moves Output: True if path is a loop, False otherwise Examples: >>> is_loop ('FFLLFF') True >>> is loop ('FFRFRFFRF') True >>> is_loop ('FRFF') False >>> is_loop ("') True >>> is_loop ('F') False >>> is_loop ('L') True