6.2 Refer to the alligator food choice example in Section 6.1.2. Using the model fit, estimate an odds ratio that describes the effect of lengthon primary food choice being either "invertebrate" or "other."

This is a question from Agresti's book An Introduction to categorical data analysis (Third edition).

Section 6.1.2 tests the multinomial model using the food choice "other" as the reference category (There are three categories: Fish, Invertebrate, and Other); but this question is asking me to use the model they tested to estimate an odds ratio that describes the effect of lengthon primary food choice being either "invertebrate" or "other." I don't know how to solve this problem.