You are given N pairs of numbers. In every pair, the first number is always smaller than the second number. A pair (c, d) can follow another pair (a, b) if b < c. Chain of pairs can be formed in this fashion. You have to find the longest chain which can be formed from the given set of pairs.

Example 1:
Input:
N = 5
P[] = {5 24 , 39 60 , 15 28 , 27 40 , 50 90}
Output: 3
Explanation: The given pairs are { {5, 24}, {39, 60},
{15, 28}, {27, 40}, {50, 90} },the longest chain that
can be formed is of length 3, and the chain is
{{5, 24}, {27, 40}, {50, 90}}
Example 2:
Input:
N = 2
P[] = {5 10 , 1 11}
Output: 1
Explanation:The max length chain possible is only of
length one.

Your Task:
You don't need to read input or print anything. Your task is to Complete the function maxChainLen() which takes a structure p[] denoting the pairs and n as the number of pairs and returns the length of the longest chain formed.

Expected Time Complexity: O(Nlog(N))
Expected Auxiliary Space: O(1)
Constraints:
1<=N<=10^{5}

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