sub obvious{
#  (explained : count from zero until Z, return the current count if we found the position we are looking for)
    #        1         2         3         4         5         6
    #23456789012345678901234567890123456789012345678901234567890
    $n=pop;for(;$n ne((0..9),(A..Z))[$a];$a++){}"$a"||0;
}