Unique Numbers

Count sequence elements whose value occurs exactly once in the entire sequence.

Input

The first line contains n (1 ≤ n ≤ 1000000). The second line contains n positive integers aᵢ ≤ 10^9.

Output

Print the number of elements that occur exactly once.

Example 1

Input

5
1 2 2 3 1

Output

1

Example 2

Input

1
7

Output

1