2. The table below shows the valuation of 2 buyers B1 and B2 for 2 different houses sold by sellers S1 and S2, where valuations a,b,c,d are non-negative integers. Assume you are following the procedure to find market clearing prices and you find that after you set all prices to zero, the preferred seller's graph does not have a perfect matching. What is the minimum number of price-incrementing rounds required to find market clearing prices? Express the answer as a single expression in terms of a,b,c, and d. Explain why your statement works for any set of non- negative integers {a,b,c,d}. Hint: Functions like min, max, absolute value, etc. may be helpful. Buyer Valuation for S1's house Valuation for S2's house B1 a b B2 C d