Given a number N, the task is to find the largest prime factor of that number.

Example 1:

Input:
N = 5
Output:
5
Explanation:
5 has 1 prime factor 
i.e 5 only.

Example 2:

Input:
N = 24
Output:
3
Explanation:
24 has 2 prime factors 
3 and 2 in which 3 is 
greater

Your Task:
You don't need to read input or print anything. Your task is to complete the function largestPrimeFactor() which takes an integer N as input parameters and returns an integer, largest prime factor of N.

Expected Time Complexity: O(sqrt(N))
Expected Space Complexity: O(1)

Constraints:
2 <= N <= 10^5