**Time limit:**1.00 s**Memory limit:**512 MB

A company wants to hire a programmers and b artists.

There are a total of n applicants, and each applicant can become either a programmer or an artist. You know each applicant's programming and artistic skills.

Your task is to select the new employees so that the sum of their skills is maximum.

# Input

The first input line has three integers a, b and n: the required number of programmers and artists, and the total number of applicants.

After this, there are n lines that describe the applicants. Each line has two integers x and y: the applicant's programming and artistic skills.

# Output

Print one integer: the maximum sum of skills.

# Constraints

- 1 \le n \le 2 \cdot 10^5
- 0 \le a,b \le n
- a+b \le n
- 1 \le x,y \le 10^9

# Example

Input:

2 1 4 3 7 9 8 1 5 4 2

Output:

20

Explanation: An optimal solution is to hire two programmers with skills 9 and 4 and one artist with skill 7. The sum of the skills is 9+4+7=20.