A sequence $a_1, a_2, \dots, a_n$ is called good if, for each element $a_i$, there exists an element $a_j$ ($i \ne j$) such that $a_i+a_j$ is a power of two (that is, $2^d$ for some non-negative integer $d$).
For example, the following sequences are good:
* $[5, 3, 11]$ (for example, for $a_1=5$ we can choose $a_2=3$. Note that their sum is a power of two. Similarly, such an element can be found for $a_2$ and $a_3$),
* $[1, 1, 1, 1023]$,
* $[7, 39, 89, 25, 89]$,
* $[]$.
Note that, by definition, an empty sequence (with a length of $0$) is good.
For example, the following sequences are not good:
* $[16]$ (for $a_1=16$, it is impossible to find another element $a_j$ such that their sum is a power of two),
* $[4, 16]$ (for $a_1=4$, it is impossible to find another element $a_j$ such that their sum is a power of two),
* $[1, 3, 2, 8, 8, 8]$ (for $a_3=2$, it is impossible to find another element $a_j$ such that their sum is a power of two).
You are given a sequence $a_1, a_2, \dots, a_n$. What is the minimum number of elements you need to remove to make it good? You can delete an arbitrary set of elements.
## Input
The first line contains the integer $n$ ($1 \le n \le 120000$) — the length of the given sequence.
The second line contains the sequence of integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^9$).
## Output
Print the minimum number of elements needed to be removed from the given sequence in order to make it good. It is possible that you need to delete all $n$ elements, make it empty, and thus get a good sequence.
[samples]
## Note
In the first example, it is enough to delete one element $a_4=5$. The remaining elements form the sequence $[4, 7, 1, 4, 9]$, which is good.
一个序列 $a_1, a_2, dots.h, a_n$ 被称为好的,如果对于每个元素 $a_i$,都存在一个元素 $a_j$($i != j$),使得 $a_i + a_j$ 是 2 的幂(即 $2^d$,其中 $d$ 为某个非负整数)。
例如,以下序列是好的:
根据定义,空序列(长度为 $0$)是好的。
例如,以下序列不是好的:
给你一个序列 $a_1, a_2, dots.h, a_n$。你需要删除最少多少个元素才能使其变好?你可以删除任意一组元素。
第一行包含整数 $n$($1 lt.eq n lt.eq 120000$)——给定序列的长度。
第二行包含整数序列 $a_1, a_2, dots.h, a_n$($1 lt.eq a_i lt.eq 10^9$)。
请输出为使序列变好所需删除的最少元素数量。可能需要删除所有 $n$ 个元素,使其变为空序列,从而得到一个好序列。
## Input
第一行包含整数 $n$($1 lt.eq n lt.eq 120000$)——给定序列的长度。第二行包含整数序列 $a_1, a_2, dots.h, a_n$($1 lt.eq a_i lt.eq 10^9$)。
## Output
请输出为使序列变好所需删除的最少元素数量。可能需要删除所有 $n$ 个元素,使其变为空序列,从而得到一个好序列。
[samples]
## Note
在第一个例子中,只需删除一个元素 $a_4 = 5$。剩余元素构成序列 $[ 4, 7, 1, 4, 9 ]$,它是好的。
**Definitions**
Let $ n \in \mathbb{Z}^+ $ be the length of the sequence.
Let $ A = (a_1, a_2, \dots, a_n) $ be a sequence of positive integers, where $ a_i \in [1, 10^9] $.
A sequence is **good** if for every element $ a_i \in A $, there exists another element $ a_j \in A $ (with $ j \ne i $) such that $ a_i + a_j = 2^d $ for some $ d \in \mathbb{Z}_{\ge 0} $.
**Constraints**
1. $ 1 \le n \le 120000 $
2. $ 1 \le a_i \le 10^9 $ for all $ i \in \{1, \dots, n\} $
**Objective**
Find the minimum number of elements to remove from $ A $ such that the resulting sequence is good. Equivalently, find the maximum size of a subset $ S \subseteq A $ such that for every $ x \in S $, there exists $ y \in S \setminus \{x\} $ with $ x + y = 2^d $ for some $ d \ge 0 $. Then, the answer is $ n - |S| $.