A number k is called a square number if for some value of d > 1, k % (d*d) = 0.
Given a number N, find the total number of positive square numbers less than or equal to N.

Example 1:
Input:
N = 3
Output:
0
Explanation:
There are no square numbers which
are less than or equal to 3.
Example 2:
Input:
N = 4
Output:
1
Explanation:
4 is the only square number less than
or equal to 4.
4 is divisible by (2*2).

Your Task:
You don't need to read input or print anything. Your task is to complete the function sqNum() which takes an Integer N as input and returns the number of square numbers less tha or equal to N.

Expected Time Complexity: O(sqrt(N)*log(N) )
Expected Auxiliary Space: O(sqrt(N))

Constraints:
1 <= N <= 10^{9}

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