DIRS = [
    (1,0),
    (0,1),
    (-1,0),
    (0,-1),
]


class Solution:
    def isRobotBounded(self, instructions: str) -> bool:
        d = 0
        px = py = 0
        for c in instructions:
            if c == "G":
                px += DIRS[d][0]
                py += DIRS[d][1]
            else:
                d += 1 if c == "L" else 3
                d %= 4

        #print(d, px, py)

        if px == py == 0:
            return True
        if d == 0:
            return False