Using python create a class and method(s) that perform the following

Inputs five grades of an student from keyboard v1,v2,v3,v4,v5. The formula for the final grade is as follows: grade=v10.25+v20.2+v30.4+v40.1+v50.05 Write a program that print the final grade and the letter (assume: A (90-100), B (80-89), C (7079), D (60-69), F (0-59)) - Use two methods (grade and letter)