Maximum Buyers Problem

There are \(n\) students and \(m\) items in a store. The \(i\)-th student has \(w_i\) money and the \(j\)-th item costs \(c_j\) money. Each student can buy at most one item and each item can be bought at most once. Determine the maximum number of students who can purchase an item.

Constraints:

• \(1 \leq n, m \leq 10^5\)
• \(1 \leq w_i, c_j \leq 10^9\)

Hint: A greedy strategy works by sorting both the students' amounts and the item prices.

inputFormat

The input consists of three lines:

1. The first line contains two integers \(n\) and \(m\).
2. The second line contains \(n\) integers, where the \(i\)-th integer is \(w_i\) — the amount of money the \(i\)-th student has.
3. The third line contains \(m\) integers, where the \(j\)-th integer is \(c_j\) — the cost of the \(j\)-th item.

outputFormat

Output a single integer: the maximum number of students who can purchase an item.

sample

3 3
3 1 2
2 1 4

2