Lido manufactures A and B from a joint process $($cost $=$ $$94,000).$ Five thousand pounds of A can be sold at split$-$off for $$20$ per pound or processed further at an additional cost of $$20,000$ and then sold for $$25.$ Ten thousand pounds of B can be sold at split$-$off for $$15$ per pound or processed further at an additional cost of $$40,000$ and later sold for $$17.$ If Lido decides to process B beyond the split$-$off point, operating income will decrease by: