Given an int percent, return the letter grade for that percent according to the following rules: (90 to 100 - A) (80 to 89 - B) (70 to 79 - C) (60 to 69 - D) (0 to 59 - F) You may assume that percent is an integer from 0 to 100. You must use a switch statement. Look at the hint if you want to make this a much easier problem.