New Numbers

A new number is a number that is not a permutation of any smaller number. 869 is not a new number because it is just a permutation of smaller numbers, 689 and 698. 509 is a new number because it can't be formed by a permutation of any smaller number (leading zeros not allowed).

Write a function that takes a non-negative integer and returns true if the integer is a new number and false if it is not.

Examples

isNew(3) ➞ true

isNew(30) ➞ true

isNew(321) ➞ false

isNew(123) ➞ true

Notes

A curious fact: out of the first one million integers, only 8002 are new.