def getIntersection(set_item1, set_item2):
    (l11, l12) = set_item1
    (l21, l22) = set_item2
    if (l11 > l21 and l11 < l22) or (l12 > l21 and l12 < l22) or (l21 > l11 and l21 < l12) or (l22 > l11 and l22 < l12):
        if l11 > l21:
            start = l11
        else: start = l21

        if l12 > l22:
            end = l22
        else:
            end = l12
        return (start ,end)
    return None

def returnInersection(set1, set2):
    for l1 in set1:
        for l2 in set2:
            ret = getIntersection(l1, l2)
            if ret:
                print ret