You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Guinea-Bissau

Context:
Rice is a staple in the diet of residents near the coast and millet a staple in the interior. Fish, shellfish, fruits and vegetables are commonly eaten along with cereal grains, milk, curd and whey. The Portuguese encouraged peanut production. Vigna subterranea (Bambara groundnut) and Macrotyloma geocarpum (Hausa groundnut) are also grown. Black-eyed peas are also part of the diet. Palm oil is harvested.

Question:
What grain is a staple for residents in the interior of Guinea-Bissau?

millet