Given two integers X and K. The task is to find smallest K-digit number divisible by X.
Note: It is given that number of digits in X is always smaller or equal to K.

Example 1:
Input:
X = 6, K = 1
Output:
6
Explanation:
6 is the smallest 1 digit number
which is divisible by 6.
Example 2:
Input:
X = 5, K = 2
Output:
10
Explanation:
10 is the smallest 2 digit number
which is divisible by 5.

Your Task:
You don't need to read input or print anything. Your task is to complete the function smallestKDigitNum() which takes 2 Integers X and K as input and returns the answer.

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

Constraints:
1 <= X <= 10^{5}
1 <= K <= 18

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