For an empty set $S$, you need to process $q$ queries:
- `1 x`: If the set does not contain $x$ at this point, add the element $x$ to the set. Otherwise, remove $x$ from the set
- `2`: Find the median in the set. If the elements are sorted in ascending order, and $n$ is the number of elements in the set, if $n$ is odd, the median is the element at index $\frac{n + 1}{2}$; if $n$ is even, the median is the average of the elements at indices $\frac{n}{2}$ and $\frac{n}{2} + 1$. The set $S$ at this point has at least one element. Index starts with $1$.
### Input
- The first line contains an integer $q$.
- The next $q$ lines, each containing a query in the specified format.
### Output
- Print a number as the answer for each query of type $2$. If the answer is a real number, round it to one decimal place.
### Constraints
- $1 \le q \le 10^5$.
- $1 \le x \le 10^9$.
### Sample test
Input
```
8
1 5
2
1 6
2
1 5
1 8
1 10
2
```
Output:
```
5
5.5
8
```
