Generate a 3 letter usernames with the following format: [first letter] + [random letter] + [last letter].
Abdul
"Aal" could be one of many potential three-letter usernames which respects the specified format.
Complete the following task based on the instruction and optional input provided.### Instruction:
Generate a 3 letter usernames with the following format: [first letter] + [random letter] + [last letter].

### Input:
Abdul

### Output:
"Aal" could be one of many potential three-letter usernames which respects the specified format.