Help me in solving SPCP4 problem

help
,
1

My issue

gcd method ?

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
	{
		// your code goes here
		Scanner sc = new Scanner(System.in);
		int T = sc.nextInt();
		for(int i=1; i<=T; i++){
		    int N = sc.nextInt();
		    int X = sc.nextInt();
		    int K = sc.nextInt();
		    int Y = N-X;
		    
		}
	}
}

Problem Link: Am I Lucky! Practice Coding Problem - CodeChef

2

@slash495
plzz refer the following solution for better understanding of the logic

/* 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
	{
		// your code goes here
		Scanner sc=new Scanner(System.in);
		int t=sc.nextInt();
		while(t-->0)
		{
		    int n=sc.nextInt();
		    int boys=sc.nextInt();
		    int k=sc.nextInt();
		    int girls=n-boys;
		    boys%=k;
		    girls%=k;
		    int dance=Math.min(boys,girls);
		    int ans=(boys-dance)+(girls-dance);
		    System.out.println(ans);
		}
	}
}