In a array A of size 2N, there are N+1 unique elements, and exactly one of these elements is repeated N times.
Return the element repeated N times.
Example 1:
Input: [1,2,3,3] Output: 3
Example 2:
Input: [2,1,2,5,3,2] Output: 2
Example 3:
Input: [5,1,5,2,5,3,5,4] Output: 5
Note:
4 <= A.length <= 100000 <= A[i] < 10000A.lengthis even