A monopolist's marginal revenue curve crosses its marginal cost curve at $20 per unit and 1 million units. The?

A monopolist's marginal revenue curve crosses its marginal cost curve at $20 per unit and 1 million units. The price that consumers are willing to pay is $30 per unit. If it produces this output, the firm's average total cost is $35 per unit and it's average fixed cost is $4 per unit. What is the producer's profit-maximizing output? what are the economic profits or loses?