Given phrases that describe the relationship between two words/phrases as options, extract the word/phrase pair and the corresponding lexical relationship between them from the input text. The output format should be "relation1: word1, word2; relation2: word3, word4". Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

Delta Air Lines will radically change its SkyMiles frequent flier program next year, becoming the first of the "big three" U.S. airlines to ditch a fixed miles-for-a-free-flight system in favor of a supply-and-demand scheme that may require more mileage points to fly on more popular routes.

Answer: operator: SkyMiles, Delta Air Lines