A university's computer system assigns user names according to the following set of rules:
The maximum length of a username is MAXLEN characters. (The value of MAXLEN will be specified in the input for each problem instance.)
The first character of the user name is the first letter of the person's first name, converted to lower case. Ignore apostrophes and hyphens here and in Step 3.
Append as many letters of the person's last name as possible (converted to lower case, if necessary), without exceeding a total of MAXLEN characters. Starting with the first letter of the last name, append these letters in the order in whch they appear in the last name.
If a user name assigned on basis of Rules 1 - 3 already exists in the database, break the tie as follows: append serial numbers 1 - 9, in that order, to the username from step 3, if that can be done without exceeding the limit of MAXLEN characters in the username. Otherwise, drop the last letter before appending the serial number.
If a user name assigned on basis of Rules 1 - 4 already exists in the database, break the tie as follows: append serial numbers 10 - 99, in that order, to the username from step 3, if that can be done without exceeding the limit of MAXLEN characters in the username. Otherwise, drop the last letter or the last two letters (whichever is necessary) before appending the serial number.
It is assumed that the above rules will avoid ties.