Cross-List Out-Of-Order Pair Count

Two sensors A and B each emit a non-decreasing stream of timestamps. To audit ordering, count how many pairs (i, j) — one index into stream A and one into stream B — have A[i] > B[j].

Input format

Line 1: two integers n and m, the lengths of streams A and B. Line 2: n non-decreasing integers, stream A. Line 3: m non-decreasing integers, stream B.

Output format

A single integer: the number of pairs with A[i] > B[j].

Constraints

• 1 ≤ n, m ≤ 100000
• -1000000000 ≤ each value ≤ 1000000000
• Both streams are given in non-decreasing order.