Given a text passage, come up with an appropriate title for it. The title should accurately represent what the main focus of the passage is. The title of a passage may be present in the first few sentences of the passage and/or be referred to multiple times in the passage. The title should be 1-5 words long.

Ex Input:
The Catechism of a Revolutionary refers to a manifesto written by Russian revolutionary Sergey Nechayev between April and August 1869 .

Ex Output:
Catechism of a Revolutionary

Ex Input:
Nucleotides are organic molecules that serve as the monomer units for forming the nucleic acid polymers deoxyribonucleic acid ( DNA ) and ribonucleic acid ( RNA ) , both of which are essential biomolecules in all life - forms on Earth . Nucleotides are the building blocks of nucleic acids ; they are composed of three subunit molecules : a nitrogenous base , a five - carbon sugar ( ribose or deoxyribose ) , and at least one phosphate group . They are also known as phosphate nucleotides .

Ex Output:
Nucleotide

Ex Input:
'' Wonderful Tonight '' is a ballad written by Eric Clapton . It was included on Clapton 's 1977 album Slowhand . Clapton wrote the song about Pattie Boyd . The female vocal harmonies on the song are provided by Marcella Detroit ( then Marcy Levy ) and Yvonne Elliman .

Ex Output:
Wonderful Tonight