SOLVE THIS QUESTION IN JAVA WITHOUT USING HASHMAP AND SCANNER

Question : Write a client that creates a symbol table mapping letter grades to numerical scores, as in the table below, then reads from standard input a list of letter grades and computes and prints the GPA (the average of the numbers corresponding to the grades). A+ A A- B+ B B- C+ C C- D F 4.33 4.00 3.67 3.33 3.00 2.67 2.33 2.00 1.67 1.00 0.00