12534
Work began on March 22 , 1884 in honour of Kaiser William I 's 87th birthday , and construction took five years .
 William I
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 William I