THE SMART TRICK OF 12345ASDF THAT NOBODY IS DISCUSSING

We look for the placement p of every character on the input within a string S in which the keyboard rows are interleaved: the primary four characters are '1QAZ' (initially column from the keyboard), the subsequent four people are '2WSX' (2nd column here on the keyboard) and so on. Unused positions are padded with underscores and the last kinds are