What does Unexpected Matlab expression mean?

This is my code.

formatPlanet = input('What is the name of the exoplanet? ');

This is all I have so far but each time I try to input a planet name (ex: Kepler-452b) it keeps giving me the unexpected message. What should I do and how can I fix this code.

Answer 1

[Walter Roberson]

formatPlanet = input('What is the name of the exoplanet? ', 's');