There are 102 keys in a standard QWERTY keyboard.
If your first language is English, you should know that the first letter of the English alphabet is A. If your first language is Spanish or French, then you should know that the first letter of those languages’ alphabets is “a”. And so forth for all other languages. Every row on a QWERTY keyboard maps to either an ‘A’ or ‘a’. The only exceptions to this rule are row 3 and row 15 – row 3 has no letters assigned because it’s where most people put their hands when not typing and row 15 is just another column that we won’t be considering here.