Using words to explain what you want would be useful, rather than leaving it up to the reader to guess.
Also using comments in your code would be useful to explain what it is doing (the big picture).
A guess, that you want the minimum of the Distance values calculated at each step of your k loop. In that case, simply store the values into an array and take the minimum:
Distance = zeros(1, n);
for k = 1:n
Distance(k) = sum(d(s));
min_Distance = min(Distance)