liwi likes a specific type of sequence. He likes an array ~A~ with length ~N~ if it meets the following conditions:

• For each element ~x~ in ~A~, ~x~ must occur exactly ~x~ times.

You are given an array ~V~ with length ~N~. liwi wants you to remove the minimum number of elements such that the result is a sequence liwi likes.

For example, ~(4, 4, 4, 4)~, ~()~, ~(3, 1, 3, 3)~ are all valid sequences liwi likes.

Constraints

• ~1 \le N \le 10^5~
• ~1 \le A_i \le 10^9~, ~A_i~ is a positive integer

For 20% of the points, ~1 \le N \le 100~, and ~1 \le A_i \le 100~.

Input Specification

The first line will contain a single integer, ~N~.

The next line of input will contain ~N~ space separated integers, ~A_i~, such that ~A_1, A_2, \dots, A_N~.

Output Specification

You are to output a single integer - the minimum number of elements that need to be removed such that the array ~A~ becomes a sequence liwi likes.

Sample Input 1

5
1 2 2 3 1

Sample Output 1

2