Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What was the Int'l Debut for a player in the back position, that also had a Cross Code Debut of RU Australia v Wales?

### Inputs:
table_name: table, columns: ['Player', "Int'l Debut", 'Year', 'Cross Code Debut', 'Date', 'Position']

### Response:
SELECT Int'l Debut FROM table WHERE Position = back AND Cross Code Debut = ru australia v wales