def flippingMatrix(matrix):
    rows = len(matrix)
    cols = len(matrix[0])
    sum = 0
    for i in range(0, rows//2):
        for j in range(0, cols//2):
            sum += max(matrix[i][j], matrix[i][cols-j-1], matrix[rows-1-i][j], matrix[rows-1-i][cols-1-j])
    
    return sum