## AUCSE012 - Student Proxy

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There are N students in a class.
All the students have different expertise in giving proxies(I hope this term is clear).
Precisely, we associate an integer P with every student which denotes the number of proxies he can make.
All students are capable of making proxies for any other student.A

A Proxy in context of class attendance refers to the act when a student who is present in a class makes attendance for a student who is absent in the same class.

There are N students in a class.

All the students have different expertise in giving proxies.

Precisely, we associate an integer P with every student which denotes the number of proxies he can make.

All students are capable of making proxies for any other student.

### Input

First line contains an integer N(1 <= N <= 1000000) denoting the total number of students.

Then, N lines follow each containing an integer Ai(1 <= Ai <= 100). The integer Ai on the ith line denotes the number of proxies that the ith student can make.

### Output

Print the minimum number of students that can be present in the class such that by giving proxies the recorded attendance can be 100%.

### Example

```Input:
5```
`1`
`3`
`2`
`1`
```2

Output:
2```

Explanation, one possible solution is that the first and second student are present. Now first student can give 1 proxy and second can give 2 proxies making the recorded attendance 5. Francky: 2012-04-14 10:22:39 There is some Ai equal to 0. It cost me some WA !!! It's a real challenge in Python, reading in time is hard ! Nitin Sharma: 2012-04-14 10:22:39 should be moved to tutorial !! Suraj D: 2012-04-14 10:22:39 tutorial for sure!! Last edit: 2012-04-10 12:13:32