1275
Since by Frobenius reciprocity and is the character of the permutation action , a permutation group defines a Gelfand pair if and only if the permutation character is a so-called " multiplicity-free " permutation character .
 person: Frobenius; person: Gelfand
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 person: Frobenius; person: Gelfand