717
Martin State Airport is linked to downtown Baltimore by two major highways I-95 and U.S. Route 40 and  MARC  commuter rail service between Baltimore's Penn Station and its nearby Martin State Airport  MARC Train  stop .
 alternate names: MARC, MARC Train
Given a phrase that describes the relationship between two words, extract the words and the lexical relationship between them. The output format should be "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
Answer:
 alternate names: MARC, MARC Train