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

### Instruction:
When a private individual is the source and 018 is the story number what is the total footage remaining from missing episodes (mm:ss)?

### Inputs:
table_name: table, columns: ['Doctor', 'Season', 'Story no.', 'Serial', 'Number of episodes', 'Total footage remaining from missing episodes (mm:ss)', 'Missing episodes with recovered footage', 'Country/Territory', 'Source', 'Format', 'Total footage (mm:ss)']

### Response:
SELECT Total footage remaining from missing episodes (mm:ss) FROM table WHERE Story no. = 018 AND Source = Private individual