class Solution:
    def checkStraightLine(self, coordinates: List[List[int]]) -> bool:

        if not coordinates:
            return False
        x1,y1 = coordinates[0]
        slope = None
        for x2,y2 in coordinates[1:]:
            if (x2-x1)==0:
                return False
            if slope is None:
                slope = (y2-y1)/(x2-x1)
                continue

            if slope != (y2-y1)/(x2-x1):
                return False
        return True
