Given two arrays X and Y of positive integers, find the number of pairs such that x^y > y^x (raised to power of) where x is an element from X and y is an element from Y.

Example 1:

Input: 
M = 3, X[] = [2 1 6] 
N = 2, Y[] = [1 5]
Output: 3
Explanation: 
The pairs which follow xy > yx are 
as such: 21 > 12,  25 > 52 and 61 > 16 .

Example 2:

Input: 
M = 4, X[] = [2 3 4 5]
N = 3, Y[] = [1 2 3]
Output: 5
Explanation: 
The pairs for the given input are 
21 > 12 , 31 > 13 , 32 > 23 , 41 > 14 , 
51 > 15 .

Your Task:
This is a function problem. You only need to complete the function countPairs() that takes X, Y, M, N as parameters and returns the total number of pairs.

Expected Time Complexity: O((N + M)log(N)).
Expected Auxiliary Space: O(1).

Constraints:
1 ≤ M, N ≤ 10⁵
1 ≤ X[i], Y[i] ≤ 10³