A vampire number is a number v that is the product of two numbers x and y such that the following conditions are satisfied:

1. at most one of x and y is divisible by 10;
2. x and y have the same number of digits; and
3. The digits in v consist of the digits of x and y (including any repetitions).

If these conditions are met, x and y are known as "fangs" of v. For example, 1260 is a vampire number because 1260 = 21*60, so 21 and 60 are the fangs.

Write a function that determines whether two numbers are fangs of a vampire number.

See also: 1825. Find all vampire fangs and 1826. Find vampire numbers.