Gabi and Luke want to use a code to send secret messages to each other. In the code, each letter of the alphabet is represented by a one-digit number, as follows:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 0 | 1 | 2 | 3 | 4 | 5 | 6 |
For example, the word BELL would be written in the code as 2-5-2-2.
To test the system, Gabi writes four words in the code and sends them to Luke. Luke tries to decode them, and gets the following answers:
TOOK
DONE
HIGH
SORT
Luke is confident that he has three of these words correct, but he is unsure about the other one.