## Phone Number, alphanumeric (Phoneword)

### Description

"Phonewords [...] are alphanumeric equivalents of a telephone number. In many countries, there exist letters corresponding to each digit on a telephone keypad. The letters corresponding to a particular telephone number can form a word, a partial word, an acronym, abbreviation, or an alphanumeric combination; these are known as phonewords."

See also http://en.wikipedia.org/wiki/Phoneword
Text published under the conditions described at http://creativecommons.org/licenses/by-sa/3.0/deed.de

### Range

for the input: 0-9, a-z, A-Z

for the output: 0-9

### Examples

555-HELP [Phone# (alphanumerical)] = 555-4357 [Phone# (numerical)]