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

### Instruction:
How many parties match the canididates listed as howard baker, sr. (r) 68.9% boyd w. cox (d) 31.1%?

### Inputs:
table_name: table, columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']

### Response:
SELECT COUNT Party FROM table WHERE Candidates = Howard Baker, Sr. (R) 68.9% Boyd W. Cox (D) 31.1%