This is my code and please modify this to work.

import java.util.Scanner;

public class Project4 {

public static void main(String[] args) {

// TODO Auto-generated method stub

Scanner hi = new Scanner(System.in); //I just use scanner with name of "Daeyoo".

while(kim.hasNextLine())

{

String str = hi.nextLine();

double a = hi.nextDouble();

double b = hi.nextDouble();

double sum = a+b;

double power = Math.pow(a,b);

double average = sum/2;

if(str.equals("+"))

{

System.out.printf("+ %.2e + %.2e = %.2e ",a,b,sum);

}

else if(str.equals("power"))

{

System.out.printf("%.2e power %.2e = %.2e ", a,b,power);

}

else if(str.equals("average"))

{

System.out.printf("%.2e average %.2e = %.2e ",a,b,average);

}

}

}

}