Q1 (30 pts). Write a Ct+ function named onlyLowerCase that accepts a string parameter and returns another string by removing all characters other than lower case letters in the parameter. For instance, if the parameter is "The young girl gave no clear response.", the function should return "heyounggirlgavenoclearresponse". In your main function, read a file named "input.txt" and remove all characters except lower case letters in each line and print them into "output.txt" using onlyLowerCase function. An example "input.txt" and "output.txt" is given below: input.txt University of Houston - Downtown The birch canoe slid on the smooth planks. Glue the sheet to the dark blue background. It's easy to tell the depth of a well. These days a chicken leg is a rare dish. Rice is often served in round bowls. Rice is often served in round bowls. output.txt niversityofoustonowntown hebirchcanoeslidonthesmoothplanks luethesheettothedarkbluebackground tseasytotell thedepthofawell hesedaysachickenlegisararedish iceisoftenservedinroundbowls