Given an integer n, return the nth digit of the infinite integer sequence [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, ...].
Example 1:
Input: n = 3 Output: 3
Example 2:
Input: n = 11 Output: 0 (the 11th digit is in "10")
Constraints: 1 <= n <= 2^31 - 1