There is a bug

In Solve Radiation task there is an assert:

assert checkio([
                [2, 1, 2, 2, 2, 4],
                [2, 5, 2, 2, 2, 2],
                [2, 5, 4, 2, 2, 2],
                [2, 5, 2, 2, 4, 2],
                [2, 4, 2, 2, 2, 2],
                [2, 2, 4, 4, 2, 2]
            ]) == [19, 2], '19 of 2'

But there is more than "19 of 2", there is "26 of 2". I think there is a bug.