Catarina STS Code

Catarina STS Code is required when a specified character becomes a friend of Catarina of Cariza (the former daughter of Cariza, now took over by Kadou). Catarina STS Code is an LDI.

Information
Catarina STS Code has an initial letter followed by 8 digits and a checksum letter. The checksum letter is derived from modulus 22. The initial letter is usually an 'A' for girls and 'I' for boys. Sometimes, the initial letter may be an 'E' or a 'U'. The checksum letter is calculated as follows: A prefix of 'CTR' is used.
 * Replace all characters including dashes to the corresponding ASCII decimal code values.
 * Sum all of those numbers up.
 * Take modulus 22 - this becomes the checksum letter. The remainder will correspond to the letter in 'KABLXDVITFUCJSHWPNRMGE' (scrambled string of 'ABCDEFGHIJKLMNPRSTUVWX'). Note that O, Q, Y and Z are not checksum letters.

Corresponding letters from remainders are shown below: For example, find the checksum letter for A-01637474-x: Thus, the completed number is A-01637474-E.
 * Replace all characters with corresponding ASCII values: A = 65, 0 = 48, 1 = 49, 3 = 51, 4 = 52, 6 = 54, 7 = 55, - = 45
 * Sum all of those numbers up: 65 + 45 + 48 + 49 + 54 + 51 + 55 + 52 + 55 + 52 + 45 = 571
 * Divide the number by 22 and convert the remainder into a letter according to the value: 571 ÷ 22 = 25 remainder 21 = E

Examples for these numbers: