Count Days with Odd Number of Birthdays

Given the integer date identifier of each birthday celebration, count the distinct identifiers that occur an odd number of times. The answer is a count, not a particular date value that occurs an odd number of times; there may be several dates with odd counts.

输入格式

The first line contains N, and the second line contains N integers. The original gave no bounds on the count or the date values; this site uses 0≤N≤200000 and identifiers in −10^9..10^9, treated as abstract date labels and not further restricted to 1..31 because of the birthday story.

输出格式

Output a single integer, the answer.

样例 1

输入：

5
4 8 2 8 9

输出：

3

样例 2

输入：

8
3 3 3 7 7 7 7 7

输出：

2

样例 3

输入：

0

输出：

0

样例说明

The outputs of the three public examples are, in order: 3; 2; 0. Verified by independent enumeration or direct simulation.