Initially, you have an empty multiset of segments. You need to process $q$ operations of two types: - $+$ $l$ $r$ — Add the segment $(l, r)$ to the multiset, - $-$ $l$ $r$ — Remove **exactly** one segment $(l, r)$ from the multiset. It is guaranteed that this segment exists in the multiset. After each operation, you need to determine if there exists a pair of segments in the multiset that do not intersect. A pair of segments $(l, r)$ and $(a, b)$ do not intersect if there does not exist a point $x$ such that $l \leq x \leq r$ and $a \leq x \leq b$.