Find the exact middle of a given matrix

find-middle-spot-in-matrix.py

"""
This program will find the element at the exact
middle of any columns (N) x rows (Y < N) matrix where
the number of columns and rows are odd.

# xxxxx   | # xxxxx     | # xxxx              | # xxx
# xx(x)xx | # xxxxx     | # xxxx              | # x(x)x
# xxxxx   | # No middle | # xxxx # No middle  | # xxx
"""

def find_middle(matrix: list) -> int:
    if len(matrix[0]) < len(matrix):
        return -1
    elif len(matrix[0]) % 2 == 0:
      return -1
    elif len(matrix[0]) % 2 == 1 and len(matrix) % 2 == 0:
      return -1

    return matrix[len(matrix)//2][len(matrix[0])//2]

if __name__ == "__main__":
    assert find_middle([[1,2,3,4,5],[6,7,8,9,10],[0,0,0,0,0]]) == 8
    assert find_middle([[1,2,3,4],[6,7,8,9],[0,0,0,0]]) == -1