String[] grades(String letter){
        String[] ledger = new String[2];
        double []precision = new double [1];
        int []match = {0, 1, 2, 3, 4};
        double grade = 0;
        if(letter.length()==2){
            if(letter.charAt(1) == '-'){
                //ledger[1] = String.format("%d%f", + (- 0.3));
                precision[0] = - 0.3;
            }
            else if (letter.charAt(1) == '+'){
                //ledger[1] = String.format("%d%f", + (+ 0.3));
                precision[0] = + 0.3;
        }}

        if(letter.charAt(0)=='A'){
            grade = match[4];
        }
        else if(letter.charAt(0)=='B'){
            grade = match[3];}
        else if(letter.charAt(0)=='C'){
            grade = match[2];}
        else if(letter.charAt(0)=='D'){
            grade = match[1];}
        else if(letter.charAt(0)=='F'){
            grade = match[0];}

        ledger[0] = String.format("%s", letter);
        ledger[1] = String.format("%.2f", grade + precision[0]);

        return ledger;
    }