Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

Ex Input:
sir john soane (10 september 1753 – 20 january 1837) was an english architect.

Ex Output:
john soane


Ex Input:
mother teresa (born agnes gonxha bojaxhiu, 26 august 1910 – 5 september 1997), was a roman catholic nun who started the missionaries of charity and won the nobel peace prize in 1979 for her work with people.for over forty years, she took care of needs of those without money, those who were sick, those without parents, and those dying incalcutta (kolkata), guided in part by the ideals of saint francis of assisi.

Ex Output:
mother teresa


Ex Input:
a lien ( or ) is a form of security interest attached to property to secure the payment of a debt to a creditor.

Ex Output:

lien