27173
He had begun to become familiar with North America while teaching in Mexico in the 1950 's and continued his education during an extended visit to Canada in 1969 and 1970 and to California in 1970 .
 location contains: North America, Mexico; location contains: North America, Canada
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: ethnicity, place lived, geographic distribution, company industry, country of administrative divisions, administrative division of country, location contains, person of company, profession, ethnicity of people, company shareholder among major shareholders, sports team of location, religion, neighborhood of, company major shareholders, place of death, nationality, children, company founders, company founded place, country of capital, company advisors, sports team location of teams, place of birth 
Text: {0} 
 Entity Pairs:  North America, Mexico; North America, Canada 
Answer:
 location contains: North America, Mexico; location contains: North America, Canada