def fingbigslope(nums):
    if nums == None:
        return
    nums = sorted(nums)
    # sorted by the 1th dimensional value
    slope = 0
    for i in range(len(nums)-1):
        axval = nums[i][0]
        ayval = nums[i][1]
        bxval = nums[i+1][0]
        byval = nums[i+1][1]
        slope_i = (byval - ayval) / float((bxval - axval))
        if abs(slope_i) > slope:
            slope = slope_i
    return slope