Problem 1: An input file (rooster.txt) containing the grades and usernames of CHEM 1234 is given as input file. The file format is the following: DOUBLE STRING For example: 28.4108 qghu88245 21.41 fdxf27614 59.02e ggbw85761 65.37 wfnf43123 Where the first column is the grade (a double value), and the second column is the username (a string). To calculate the final grade (score and letter grade), the instructor uses the following procedure: 1. Find the maximum grade (call it max), from the rooster file, 2. Calculate the final grade = grade[i]*100/max, 3. Assign a letter grade using the table below: Final grade Letter Grade [90, 100] A [80, 90) B [70, 80) [60, 70) D