def thong_ke(day):
    dem = {}
    for ma in day:
        dem[ma] = dem.get(ma, 0) + 1
    chon = min(dem, key=lambda ma: (-dem[ma], ma), default=None)
    return dem, chon

day = ["ASP", "TEST", "ASP", "ANDROID", "TEST"]
assert thong_ke(day) == ({"ASP": 2, "TEST": 2, "ANDROID": 1}, "ASP")
assert thong_ke(reversed(day))[1] == "ASP"
assert thong_ke([]) == ({}, None)
print(thong_ke(day))