Mahalanobis distance between two vectors in MATLAB

I have the following two vectors, and trying to find the Mahalanobis distance between them. The two vectors are as follows:

A=[2,4,5,7];

B=[6,3,8,1];

For calculating the Mahalanobis distance, I did the following:

> mahal(A(:),B(:))

For that, I got the following results:

0.6466

0.0259

0.0259

0.6466

But, how can I get one value, as when you calculate Euclidean distance for instance?

Thanks.