Suppose you are creating a butterfly spread using call options with 3 different strike prices. Currently, the call price with strike price of $40 is $22.26, the call with strike price of $50 is $10.9, and the call with strike price of $60 is $5.58.

What is the initial cash flow of the butterfly spread strategy?If it's a cash inflow, enter a positive number.If it's a cash outflow, enter a negative number