In this term, Alice took courses. Now, she has finished all final exams, and she will get her grades in the following days.

On the i-th day, Alice will know her grade of the i-th course, denoted as . If is strictly less than the average grade of the first courses, Alice will be sad on that day.

Now Bob hacks into the school's database. Bob can choose a set of courses ( can be empty), and then for each course in , change Alice's grade from to .

Bob wants to minimize the number of days that Alice will be sad. Now you need to help him to decide which courses' grades he should modify.

Note: Alice is always happy on the first day. 

The first line contains one single integer .

Then  lines follow. The i-th line contains 2 integers .

The input guarantees that ，.

Output the minimum number of the days that Alice will be sad.

4
1 2
2 3
1 2
1 1

1