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

### Instruction:
How many frequencies have a line of East London and destination of Crystal Palace?

### Inputs:
table_name: table, columns: ['Platform', 'Frequency (per hour)', 'Destination', 'Service Pattern', 'Operator', 'Line']

### Response:
SELECT COUNT Frequency (per hour) FROM table WHERE Line = east london AND Destination = crystal palace