Smallest factorial number
Easy Accuracy: 16.58% Submissions: 169 Points: 2

Given a number n. The task is to find the smallest number whose factorial contains at least n trailing zeroes.

Example 1:

Input:
n = 1
Output: 5
Explanation : 5! = 120 which has at
least 1 trailing 0.

Example 2:

Input:
n = 6
Output: 25
Explanation : 25! has at least
6 trailing 0.


User Task:
Complete the function findNum() which takes an integer N as input parameters, and returns the answer.

Expected Time Complexity: O(log2 N * log5 N).
Expected Auxiliary Space: O(1).

Constraints:
1 <= n <= 104

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