Given N, find s such that sum of first s natural number is N.

Example 1:
Input: N = 10
Output: 4
Explanation: Sum of first 4 natural
number is 1 + 2 + 3 + 4 = 10.
Example 2:
Input: N = 17
Output: -1
Explanaion: There is no such number.

Your Task:
You don't need to read or print anyhting. Your task is to complete the function find() which takes N as input parameter and returns s. If not possible return -1.

Expected Time Complexity: O(log(N))
Expected Space Complexity: O(1)
Constraints:
1 <= N <= 10^{9}

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