Can you give an example of how the coupon redemption works for a-la carte offers on main dish?

Let's say if 2 people are dining and you order a seafood main dish and a vegetarian main dish, then the vegetarian main dish (assumed to be less expensive) shall be complimentary with 1 coupon. Now if you are 4 people, and you order 2 main dishes of Rs.500 each and 2 main dishes of Rs.300 each, then you can redeem 2 coupons and both the Rs.300 dishes shall be complimentary.