INDICATORS ON 12345ASDF YOU SHOULD KNOW

We seek out the placement p of every character in the enter inside a string S where the keyboard rows are interleaved: the primary four people are '1QAZ' (first column on the keyboard), the following 4 people are '2WSX' (2nd column of the keyboard) etc. Unused positions are padded with underscores and the final types are simply just discarded. Thi