public class s {

    public int val;
    public s left;
    public s right;


	public s(int val, s left, s right) {
		this.val = val;
		this.left = left;
		this.right = right;
    }

    public s(int val) {
		this.val = val;
    }


    public static int conta(s A) {

        int conta = 0;
        boolean f = checkUnival(A,A.val);
        if (f) {
            conta++;
        }
        if (A.left != null) {
            conta += conta(A.left);
        }

        if (A.right != null) {
            conta += conta(A.right);
        }


        return conta;
    }

    public static boolean checkUnival(s A, int i) {

        if (A.left == null && A.right == null && A.val == i) {
            return true;
        }

        if (A.val == i) {
            boolean checkLeft = true;
            boolean checkRight = true;

            if (A.left != null) {
                checkLeft = checkUnival(A.left, i);
            }

            if (A.right != null) {
                checkLeft = checkUnival(A.left, i);
            }

            return checkLeft && checkRight;
        }
        else {
            return false;
        }

    }



   public static void main(String[] args) {

        s A = new s(0);
        s B = new s(1);
        s C = new s(1);

        // s D = new s(1);
        // s E = new s(1);
        // s F = new s(1);
        // s G = new s(1);
        // s H = new s(0);

        A.left = B;
        A.right = C;
        // C.left =  D;
        // D.left = E;
        // D.right = F;


        System.out.println(conta(A));

    }

}