5501
In 1941 , while giving a series of visiting lectures at the University of Michigan , he met Samuel Eilenberg and began what would become a fruitful collaboration on the interplay between algebra and topology .
 organization: University of Michigan; person: Samuel Eilenberg
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 organization: University of Michigan; person: Samuel Eilenberg