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Sunscreen

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

Output

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

Sample Input

3 23 102 51 56 24 1

Sample Output

2

题意：有C头牛和L瓶防晒霜，分别给出C头牛需要防晒霜的范围和L瓶防晒霜的SPF和可用与多少头牛，求有多少头牛能满足要求

解题思路：优先队列和贪心，先将牛按照对防晒霜的最小需求排序，再将防晒霜按从小到大的顺序排序，对于防晒霜i来说肯定给满足条件且maxSPF最小的牛来用最划算，因为后面还有SPF更大的防晒霜，所以如果大于当前牛的minSPF则将该牛加入优先队列，让maxSPF最小的牛先出队，如果该防晒霜满足要求则先给该牛使用。

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