import java.util.Scanner;

public class Main {

    public static void main(String[] args){

    Scanner grade  = new Scanner(System.in);

    System.out.print("上次成绩： ");

    double fisrt_grade = grade.nextDouble();

    System.out.print("本次成绩： ");

    double ssecond_grade  = grade.nextDouble();

    double change = (ssecond_grade - fisrt_grade )/fisrt_grade * 100;

    System.out.printf("提高了: %.2f%% \n",change);

    }

}