Help me in solving TAXSAVING problem

My issue

can you please help me to solve

My code

/* package codechef; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Codechef
{
	public static void main (String[] args) throws java.lang.Exception
	{
		Scanner scanner = new Scanner(System.in);
		int t = scanner.nextInt();
		while(t-- >0)
		{
		    int x=scanner.nextInt();
		    int y=scanner.nextInt();
		    System.out.println(calculateMinimumInvestment(x,y));
		}// your code goes here
	}
	public static int calculateMinimumInvestment(int x,int y)
	{
	    int investment=0;
	    int diff=x-y;
	    while(diff>0)
	    {
	        investment += diff;
	        diff=diff/2;
	    }
	    return investment;
	}
}

Problem Link: Saving Taxes Practice Coding Problem - CodeChef

@r22r01a0561
just print the difference.