package acm;

public class FrogDate {

    public static void main(String[] args) {

        int x = ,y = ,m = ,n = ,l = ;

        int ar=n-m,br=,cr=x-y;

        int M = exGcd(n-m,l,ar,br);

        System.out.println("M:" + M);

        if((x-y)%M!= || m==n)

            System.out.println("Impossible");

        else{

            int s=l/M;

            ar=ar*((x-y)/M);              ar=(ar%s+s)%s;

            System.out.println("ar : " + ar);

        }

    }

    static int Gcd(int a, int b)

    {

        while(b != )

        {

            int r = b;

            b = a % b;

            a = r;

        }

        return a;

    }

    static int exGcd(int a, int b, int x, int y)

    {

        if(b == )

        {

            x = ;

            y = ;

            return a;

        }

        int r = exGcd(b, a % b, x, y);

        int t = x;

        x = y;

        y = t - a / b * y;

        return r;

    } 

}