+ محدودیت زمان: ۱ ثانیه + محدودیت حافظه: ۲۵۶ مگابایت ---------- Initially, we have an array of length $1$ containing only the number $0$. All natural numbers are listed in ascending order in the “reservation list” (the first number in the list is $1$). The array undergoes $q$ operations. The $i^{th}$ operation, is one of the following: + **Insert($p$, $x$)**: Insert the first $x$ numbers from the reservation list after the number $p$ in the array, in ascending order. These numbers are removed from the reservation list. + **Remove($p$, $x$)**: Remove the next $x$ numbers after number $p$ in the array. These numbers are not returned to the reservation list. You are given information about $q$ operations, and you are asked to determine the number written in the middle of the array after each operation. If the length of the array after the $i^{th}$ operation is $n$, you should find the $\lceil \frac n 2 \rceil^{th}$ element of the array. Note that the indexing of the array starts from $1$. # ورودی The first line contains an integer $q$, which represents the number of operations. Each of the next $q$ lines contains two integers: $p_i$, and $k_i$. If $k_i = +x$, operation **Insert($p_i$, $x$)** is executed. If $k_i = -x$, operation **Remove($p_i$, $x$)** is executed. It is guaranteed that all operations are valid, and no impossible operation is performed on the array. Additionally, at most $2 \times 10^9$ numbers are moved from the reservation list into the array. $$0 \leq p_i, |k_i| \leq 2 \times 10^9$$ $$0 \leq q \leq 5 \times 10^5$$ # خروجی Output $q$ lines. In the $i^{th}$ line, print the middle element of the array after performing the $i^{th}$ operation. # مثال ### ورودی نمونه ۱ ``` 10 0 3 0 2 5 -2 4 1 0 -2 5 2 7 3 3 2 10 5 12 20 ``` ### خروجی نمونه ۱ ``` 1 5 4 6 5 7 9 10 16 22 ```