"Please provide letters 1, 3, 5, 7 & 9 of your password"
A minute later...
"Please provide letters 2, 4, 6, 8 & 10 of your password"
"Please provide letters 1, 3, 5, 7 & 9 of your password"
A minute later...
"Please provide letters 2, 4, 6, 8 & 10 of your password"