Max Completed Tasks

You are given a set of n employees and m tasks. Each employee is characterized by two integers: the number of available hours H_i and the skill level S_i.

Each task requires a certain amount of time T_j and a minimum skill level R_j to complete. An employee can complete a task if and only if:

\( T_j \leq H_i \quad\text{and}\quad R_j \leq S_i \)

Each employee can work on tasks sequentially using his/her available working hours. The tasks and employees are processed in a sorted order based on their skill levels (and available time in case of a tie). Your goal is to determine the maximum number of tasks that can be completed by optimally assigning tasks to the employees.

inputFormat

The input is read from standard input (stdin) and has the following format:

 n m
 H1 S1
 H2 S2
 ...
 Hn Sn
 T1 R1
 T2 R2
 ...
 Tm Rm

Here, the first line contains two integers: n (the number of employees) and m (the number of tasks). The next n lines each contain two integers representing the available hours H_i and the skill level S_i of the i-th employee. The following m lines each contain two integers representing the required time T_j and required skill level R_j of the j-th task.

outputFormat

Output a single integer on standard output (stdout) — the maximum number of tasks that can be completed under the given constraints.

3 3
10 5
8 7
6 4
5 3
4 4
6 6

2