Find the Smallest Common Number

Statement

We’re given three integer arrays, each sorted in ascending order. Return the smallest number common in all three arrays. In case no number is common, return -1.

Example

Let’s look at the three arrays below, where $6$​ is the smallest number that is common in all the arrays:

Sample input

v1 = [6, 7, 10, 25, 30, 63, 64]
v2