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Given a sorted array **A[]** of **N **positive integers having all the numbers occurring exactly twice, except for one number which will occur only once. Find the number occurring only once.

**Example 1:**

**Input:
**N = 5
A = {1, 1, 2, 5, 5}**
Output: **2
**Explanation:
**Since 2 occurs once, while
other numbers occur twice,
2 is the answer.

**Example 2:**

**Input:
**N = 7
A = {2, 2, 5, 5, 20, 30, 30}
**Output: **20
**Explanation:
**Since 20 occurs once, while
other numbers occur twice,
20 is the answer.

**Your Task:**

You don't need to read input or print anything. Your task is to complete the function **search() **which takes two arguments(array A and integer N) and returns the number occurring only once.

**Expected Time Complexity: **O(Log(N)).

**Expected Auxiliary Space: **O(1).

**Constraints**

0 < **N** <= 10^6

0 <= **A[i]** <= 10^9

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