Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| District | Incumbent | Party | First elected | Result | Candidates |
| --- | --- | --- | --- | --- | --- |
| Pennsylvania 6 | Gus Yatron | Democratic | 1968.0 | Re-elected | Gus Yatron (D) 67.1% George Hulshart (R) 32.9% |
| Pennsylvania 9 | Bud Shuster | Republican | 1972.0 | Re-elected | Bud Shuster (R) Unopposed |
| Pennsylvania 11 | Ray Musto | Democratic | 1980.0 | Lost re-election Republican gain | James L. Nelligan (R) 51.9% Ray Musto (D) 48.1% |
| Pennsylvania 12 | John Murtha | Democratic | 1974.0 | Re-elected | John Murtha (D) 59.4% Charles A. Getty (R) 40.6% |
| Pennsylvania 18 | Doug Walgren | Democratic | 1976.0 | Re-elected | Doug Walgren (D) 68.5% Steven R. Snyder (R) 31.5% |
| Pennsylvania 21 | Donald A. Bailey | Democratic | 1978.0 | Re-elected | Donald A. Bailey (D) 68.4% Dirk Matson (R) 31.6% |
Question:
How many parties does the incumbent Donald A. Bailey a member of?
Answer:
1.0