Time Limit: 1s

Memory Limit: 65535k

## Description

There are N bugs to be repaired and some engineers whose abilities are roughly equal. And an engineer can repair a bug per day. Each bug has a deadline A[i]. Question: How many engineers can repair all bugs before those deadlines at least? 1<=n<= 1e6. 1<=a[i] <=1e9

## Input

There are multiply test cases. In each case, the first line is an integer N , indicates the number of bugs. The next line is n integers indicates the deadlines of those bugs.

## Output

There are one number indicates the answer to the question in a line for each case.

## Sample Input

4
1 2 3 4

## Sample Output

1

None

None