Hello!
I have wa #2. But i don't undestand my mistake.can somebody help me?
listnig is below

import java.util.Scanner;
public class q1607 {
    /**
     * @param args
     */
    public static void main(String[] args) {
        Scanner in1 = new Scanner(System.in);
        int a=in1.nextInt();
        int b=in1.nextInt();
        int c=in1.nextInt();
        int d=in1.nextInt();
        a=a-b;
        c=c+d;
        while (a<=c-d)
        {
            a=a+b;
            if (a>=c-d)
            {break;}
            c=c-d;
        }
        System.out.println(a);
    }
}