import java.util.*;
public class Back_2754 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        //given
        String grade=sc.next();
        //when
        switch(grade){
                case "A+":
                System.out.println(4.3);
                break;
                case "A0":
                System.out.println(4.0);
                break;
                case "A-":
                System.out.println(3.7);
                break;
                case "B+":
                System.out.println(3.3);
                break;
                case "B0":
                System.out.println(3.0);
                break;
                case "B-":
                System.out.println(2.7);
                break;
                case "C+":
                System.out.println(2.3);
                break;
                case "C0":
                System.out.println(2.0);
                break;
                case "C-":
                System.out.println(1.7);
                break;
                case "D+":
                System.out.println(1.3);
                break;
                case "D0":
                System.out.println(1.0);
                break;
                case "D-":
                System.out.println(0.7);
                break;
                case "F":
                System.out.println(0.0);
                break;
        }
    }
}