typedef struct _tree
{
        int val;
	struct _tree *left, *right;
}tree;


tree *t;
t = make_tree();

t.val = getint();



tree *_find(tree *_t, int _val)
{
	tree *child = make_tree();
	tree *iterator = _t;
	while(1)
	{
		if(child.val > iterator.val)
		{
			if(iterator.right == NULL)
			{
				//iterator.right = child;
				//break;
				return iterator;
			}
			else
			{
				iterator = iterator.right;
			}
		}
		if(child.val < iterator.val)
		{
			if(iterator.left == NULL)
			{
				//iterator.left = child;
				//break;
				return iterator;
			}
			else
			{
				iterator = iterator.left;
			}
		}
		if(child.val == iterator.val)return iterator;
	}
}


void insert(tree *_t, int _val)
{
	tree *t = _find(_t, _val);

	if(t.val == _val)return;

	if(_val > t.val)t.right = make_tree(_val);
	if(_val < t.val)t.left = make_tree(_val);
}

bool find(tree *_t, int _val)
{
	tree *t = _find(_t, _val);
	if(t.val == _val)return true;
	else return false;
}


main:

while(1)
{
	int i = getint();

	tree *child = make_tree();
	child.val = i;






	if(i == 0)break;
}