In Excel, the columns range from
A-Z, AA,AB,AZ,BA,..,BZ and so on. They actually each stand for numbers, but rather are encoded as alphabet strings.
In this challenge, you will be given a string of alphabets, and you must calculate the column it corresponds to.
'A' returns 1 (meaning that it is the first column)
'B' returns 2
'Z' returns 26
'AA' returns 27
'AB' returns 28
'AZ' returns 52
'ZZ' returns 702
'AAA' returns 703
You can assume that capital letters will be given only.
Shortest bytes win.