import java.util.Scanner;
public class EqualNum {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int number = Integer.parseInt(scanner.nextLine());
        int number1 = Integer.parseInt(scanner.nextLine());
        int number2 = Integer.parseInt(scanner.nextLine());
        if (number != number1) {
            System.out.println("no");

        } else if (number1 != number2) {
            System.out.println("no");
        } else  {
            System.out.println("yes");

        }
    }
}