Consider market for cars. There are $6$ consumers labeled I$=1,2...,6.$ Every consumer want to buy one car. In addition each consumer I has willingness to pay equal to $$I$.$ There are two domestic producers of cars denoted A and B firms. Firm A can produce up to $2$ cars with a constant marginal production cost equal to $2.$ Similarly firm B can produce $2$ cars with constant marginal cost of $4.$ How many cars will be produced and traded in a competitive equilibrium?