Alternative R has a first cost of $$79,000,$ annual M&O costs of $$56,000,$ and a $$20,000$ salvage value after $5$ years. Alternative S has a first cost of $$175,000$ and a $$46,000$ salvage value after $5$ years, but its annual M&O costs are not known. Determine the M&O costs for alternative S that would yield a required incremental rate of return of $23\%.$