Help me in solving LBJ208B problem logic behind th eproblem

help
,
1

My issue

My code

// Update the '_' in the code below to solve this problem
import java.util.Scanner;
class Codechef
{
	public static void main (String[] args)
	{
		int n = 10;
	    int m = 10;
	    System.out.println("The number of extra shoes that Chef has to buy is _");
	    
	    n = 5;
	    m = 10;
	    System.out.println("The number of extra shoes that Chef has to buy is _");
	    
	    n = 15;
	    m = 10;
	    System.out.println("The number of extra shoes that Chef has to buy is _");
	}
}

Learning course: Java for problem solving - 2
Problem Link: CodeChef: Practical coding for everyone