import java.util.Scanner;

public class Main { private static final String SAD_FACE = ":("; private static final String HAPPY_FACE = ":)"; public static void main(String[] args) { Scanner scan = new Scanner(System.in);

    int firstDayTemp = scan.nextInt();
    int secondDayTemp = scan.nextInt();
    int thirdDayTemp = scan.nextInt();

    int differenceOfFirstAndSecond = firstDayTemp - secondDayTemp;
    int differenceOfSecondAndThird = secondDayTemp - thirdDayTemp;

    if (differenceOfSecondAndThird < 0){
        differenceOfSecondAndThird = differenceOfSecondAndThird * (-1);
    }

    if (differenceOfFirstAndSecond< 0){
        differenceOfFirstAndSecond = differenceOfFirstAndSecond * (-1);
    }

    if((firstDayTemp > secondDayTemp)
            && (secondDayTemp <= thirdDayTemp)){

        System.out.println(HAPPY_FACE);

    }else if ((firstDayTemp < secondDayTemp)
            && (secondDayTemp >= thirdDayTemp)){

        System.out.println(SAD_FACE);

    }else if ((firstDayTemp < secondDayTemp)
            && (secondDayTemp < thirdDayTemp)
            && (differenceOfSecondAndThird < differenceOfFirstAndSecond)){

        System.out.println(SAD_FACE);

    }else if ((firstDayTemp < secondDayTemp)
            && (secondDayTemp < thirdDayTemp)
            && (differenceOfSecondAndThird > differenceOfFirstAndSecond)){

        System.out.println(HAPPY_FACE);

    }else if ((firstDayTemp > secondDayTemp)
            && (secondDayTemp > thirdDayTemp)
            && (differenceOfSecondAndThird < differenceOfFirstAndSecond)){

        System.out.println(HAPPY_FACE);

    }else if ((firstDayTemp > secondDayTemp)
            && (secondDayTemp > thirdDayTemp)
            && (differenceOfSecondAndThird >= differenceOfFirstAndSecond)){

        System.out.println(SAD_FACE);

    }else if ((firstDayTemp == secondDayTemp)
            && (secondDayTemp < thirdDayTemp)){

        System.out.println(HAPPY_FACE);

    }else if ((firstDayTemp == secondDayTemp)
            && (secondDayTemp > thirdDayTemp)){

        System.out.println(SAD_FACE);

    }

}

}