题目描述
Most of us know how to count the number of inversions in an array. An inversion in an array is a pair of indices(i,j) such that a[i]>a[j] and i < j.
In this problem you are given 2 arrays A and B and you have to return number of such pairs such that a[i]>b[j] and i < j.
Input Format:
First line contains n denoting the total number of elements.The next line contains n space separated integers of array A.This line is again followed by n space separated integers of array B.
Output Format:
Print the total number of pairs satisfying the above condition.
Constraints:
1 ≤ n ≤ 200000
1 ≤ A[i] ≤ 10^6
1 ≤ B[i] ≤ 10^6
SAMPLE INPUT
3
5 6 7
1 2 3
SAMPLE OUTPUT
3
Explanation
3 pairs are (5,2) , (5,3) and (6,3).
输入格式
见题面
输出格式
见题面