A set of n 1-dimensional items have to be packed in identical bins. All bins have exactly the same length l and each item i has length li<=l . We look for a minimal number of bins q such that
- each bin contains at most 2 items,
- each item is packed in one of the q bins,
- the sum of the lengths of the items packed in a bin does not exceed l .
You are requested, given the integer values n , l , l1 , ..., ln , to compute the optimal number of bins q .