Smallest Larger Integer That Uses None of the Digits of n

Given a positive integer `n`, return the smallest integer that is strictly greater than `n` and that contains none of the decimal digits appearing in `n`. If no such integer exists, return `-1`. ### Function Signature ```python def next_number(n: int) -> int: ``` ### Rules - Digits are read in ordinary base-10 notation, without leading zeros. - A digit is forbidden if it appears at least once in `n`. Every digit of the returned integer must be a digit that is not forbidden. The returned integer may repeat a digit any number of times, as `700000` does in Example 1. - The returned integer has no leading zeros, so its first digit is not `0`. It may have more digits than `n`. - Return `-1` exactly when no positive integer greater than `n` can be written using only digits that are not forbidden. ### Constraints - `1 <= n <= 2^31 - 1` (that is, `n` is strictly positive and less than `2147483648`) - The returned value can exceed `2^31 - 1`, so it may need a 64-bit or arbitrary-precision integer; it is always less than `10^11`. ### Examples **Example 1** ```text Input: n = 654321 Output: 700000 ``` The forbidden digits are 1, 2, 3, 4, 5 and 6. Every integer from 654322 to 699999 starts with a 6, and 700000 uses only the allowed digits 7 and 0. **Example 2** ```text Input: n = 90 Output: 111 ``` The forbidden digits are 9 and 0. Every integer from 91 to 99 contains a 9, every integer from 100 to 110 contains a 0, and 111 contains neither. **Example 3** ```text Input: n = 123456789 Output: -1 ``` The only digit that is not forbidden is 0, and no positive integer can be written with zeros alone.