import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); String grade =sc.next(); if(grade.equals("A")){ System.out.println("优秀"); }else if(grade.equals("B")){ System.out.println("良好"); }else if(grade.equals("C")){ System.out.println("及格"); }else if(grade.equals("D")){ System.out.println("不及格"); }else { System.out.println("未知等级"); } } }