Given an integer N, write a program to find the one’s complement of the integer.

Example 1:
Input:
N = 5
Output:
2
Explanation:
binary of 5 is 101
1's complement of 101 is 010
010 is 2 in its decimal form.
Example 2:
Input:
N = 255
Output:
0
Explanation:
binary of 255 is 1111 1111
1's complement of 1111 1111 is
0000 0000 which is 0 in its decimal form.
Your Task:
You don't need to read input or print anything. Your task is to complete the function onesComplement() which takes an integer N as input parameter and returns an integer value, the one's complement of N.

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

Constraints:
1 <= N <= 10^{6}

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