class Solution:
    def leftMostColumnWithOne(self, binaryMatrix: 'BinaryMatrix') -> int:

        #TC: max O(row + col)
        #SC: O(1)

        total_row, total_col = binaryMatrix.dimensions()[0], binaryMatrix.dimensions()[1]

        row = total_row - 1
        col = total_col - 1

        res = total_col

        while(row >= 0 and col >= 0):
            if binaryMatrix.get(row, col) == 1:
                res = min(res, col)
                col -= 1
            else:
                row -= 1

        if res == total_col:
            return -1
        else:
            return res