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class Solution(object):
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    def movesToChessboard(self, board):
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        N = len(board)
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        ans = 0
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        # For each count of lines from {rows, columns}...
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        for count in (
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            collections.Counter(map(tuple, board)),  # get row
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            collections.Counter(zip(*board)),
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        ):  # get column
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            # If there are more than 2 kinds of lines,
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            # or if the number of kinds is not appropriate ...
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            if len(count) != 2 or sorted(count.values()) != [N / 2, (N + 1) / 2]:
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                return -1
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            # If the lines are not opposite each other, impossible
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            line1, line2 = count
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            if not all(x ^ y for x, y in zip(line1, line2)):
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                return -1
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            # starts = what could be the starting value of line1
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            # If N is odd, then we have to start with the more
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            # frequent element
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            starts = [int(line1.count(1) * 2 > N)] if N % 2 else [0, 1]
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            # To transform line1 into the ideal line [i%2 for i ...],
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            # we take the number of differences and divide by two
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            ans += (
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                min(
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                    sum((x - i) % 2 for i, x in enumerate(line1, start))
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                    for start in starts
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                )
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                / 2
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            )
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        return ans