import java.util.Random;
public class RandomDemo {
public static void main(String[] args) {
Random r = new Random();
float random = r.nextFloat();
float random2 = random * 100;
String grade = String.format("%.1f",random2);
//System.out.println(grade);
float grade2 = Float.parseFloat(grade);
if(grade2 >= 90){
System.out.println("A");
}else if(grade2 >= 60 && grade2 < 90){
System.out.println("B");
}else{
System.out.println("C");
}
}
}