3270 - Find the Key of the Numbers\.

Easy

You are given three positive integers num1, num2, and num3.

The key of num1, num2, and num3 is defined as a four-digit number such that:

• Initially, if any number has less than four digits, it is padded with leading zeros.

• The <code>i^th</code> digit (1 <= i <= 4) of the key is generated by taking the smallest digit among the <code>i^th</code> digits of num1, num2, and num3.

Return the key of the three numbers without leading zeros (if any).

Example 1:

Input: num1 = 1, num2 = 10, num3 = 1000

Output: 0

Explanation:

On padding, num1 becomes "0001", num2 becomes "0010", and num3 remains "1000".

• The <code>1^st</code> digit of the key is min(0, 0, 1).

• The <code>2^nd</code> digit of the key is min(0, 0, 0).

• The <code>3^rd</code> digit of the key is min(0, 1, 0).

• The <code>4^th</code> digit of the key is min(1, 0, 0).

Hence, the key is "0000", i.e. 0.

Example 2:

Input: num1 = 987, num2 = 879, num3 = 798

Output: 777

Example 3:

Input: num1 = 1, num2 = 2, num3 = 3

Output: 1

Constraints:

• 1 <= num1, num2, num3 <= 9999