If I have an alphabet of size x and a password of length n there are x^n possibilities. What results in a larger set -- adding 1 more character to the alphabet

If I have an alphabet of size x and a password of length n there are x^n possibilities. What results in a larger set -- adding 1 more character to the alphabet or adding one to the length; i.e. which is bigger (x + 1)^n or x^(n+1)?