public class Draw {

    public int[] digits = new int[3];

    Random random = new Random();
    public void Pull()
    {
        for (int i = 0; i < digits.length ; i++) {
            digits[i] = random.nextInt(10);
        }
    }
}

public class Play {
    public static void main(String[] args) {
        Draw draw = new Draw();
        int counter = 0;

        while (!LuckyStrike.Won(draw)) {
            draw.Pull();

            for (int digit : draw.digits) {
                System.out.print(digit);
            }
            counter++;
            System.out.println();
        }

        System.out.println("After " + counter + " attempts you won!");
    }
}

public class LuckyStrike {
    public LuckyStrike(){

    }
    public static boolean Won(Draw draw){
        return draw.digits[0] == 7 && draw.digits[1] == 7 && draw.digits[2] == 7;
    }

}