### START FUNCTION
def sum_of_diagonals(matrix):
diag_1=0
diag_2=0
k = matrix.shape[1]-1
for i in range(matrix.shape[0]):
diag_1 += matrix[i][i]
diag_2 += matrix[i][k]
k -=1
if matrix.shape[0]%2 != 0:
mid = int(np.floor(matrix.shape[0]/2))
sum = diag_1+diag_2-matrix[mid][mid]
else:
sum = diag_1+diag_2
return sum
### END FUNCTION