Given two strings A and B, find if A is a subsequence of B.

Example 1:

Input:
A = AXY 
B = YADXCP
Output: 0 
Explanation: A is not a subsequence of B
as 'Y' appears before 'A'.

Example 2:

Input:
A = gksrek
B = geeksforgeeks
Output: 1
Explanation: A is a subsequence of B.

Your Task:
You dont need to read input or print anything. Complete the function isSubSequence() which takes A and B as input parameters and returns a boolean value denoting if A is a subsequence of B or not.

Expected Time Complexity: O(N) where N is length of string B.
Expected Auxiliary Space: O(1)

Constraints:
1<= |A|,|B| <=10⁴