55895
She later drew notoriety for obsessively stalking opera singer Birgit Nilsson for nine years ; beginning at the summer of 1968 at the Bayreuth Festival and ending upon Theobald 's suicide in 1977 .
 person: Birgit Nilsson; person: Theobald
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: location, person, organization 
Text: {0} 
 Entities: Birgit Nilsson, Theobald 
Answer:
 person: Birgit Nilsson; person: Theobald