Sunscreen POJ - 3614(防曬油) 貪心-優先佇列

To avoid unsightly burns while tanning, each of the C (1 ≤ C ≤ 2500) cows must cover her hide with sunscreen when they’re at the beach. Cow i has a minimum and maximum SPF rating (1 ≤ minSPFi ≤ 1,000; minSPFi ≤maxSPFi ≤ 1,000) that will work. If the SPF rating is too low, the cow
suffers sunburn; if the SPF rating is too high, the cow doesn’t tan at all…

The cows have a picnic basket with L (1 ≤ L ≤ 2500) bottles of sunscreen lotion, each bottle i with an SPF rating SPFi (1 ≤ SPFi ≤ 1,000). Lotion bottle i can cover coveri cows with lotion. A cow may lotion from only one bottle.

What is the maximum number of cows that can protect themselves while tanning given the available lotions?

Input

• Line 1: Two space-separated integers: C and L
• Lines 2…C+1: Line i describes cow i’s lotion requires with two integers: minSPFi and maxSPFi
• Lines C+2…C+L+1: Line i+C+1 describes a sunscreen lotion bottle i with space-separated integers: SPFi and coveri

Output

A single line with an integer that is the maximum number of cows that
can be protected while tanning

Sample Input

3 2

3 10

2 5

1 5

6 2

4 1

Sample Output

2