Who is free at 3:30 PM?
4 barbers can do Shape-up then, in the shop's own order.
No preference takes the lightest book of the 4 barbers open at 3:30 PM, so the work spreads across the shop instead of piling onto one chair.
4 barbers can do Shape-up then, in the shop's own order.
No preference takes the lightest book of the 4 barbers open at 3:30 PM, so the work spreads across the shop instead of piling onto one chair.