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 | Hugh Scott | Republican | 1946.0 | Re-elected | Hugh Scott (R) 50.6% Alexander Hemphill (D) 49.4% |
| Pennsylvania 8 | Karl C. King | Republican | 1951.0 | Re-elected | Karl C. King (R) 51.2% John P. Fullam (D) 48.8% |
| Pennsylvania 9 | Paul B. Dague | Republican | 1946.0 | Re-elected | Paul B. Dague (R) 62.7% Edward G. Wilson (D) 37.3% |
| Pennsylvania 12 | Ivor D. Fenton | Republican | 1938.0 | Re-elected | Ivor D. Fenton (R) 55.5% Charles E. Lotz (D) 44.5% |
| Pennsylvania 15 | Francis E. Walter | Democratic | 1932.0 | Re-elected | Francis E. Walter (D) 61.6% LeRoy Mikels (R) 38.4% |
| Pennsylvania 17 | Alvin Bush | Republican | 1950.0 | Re-elected | Alvin Bush (R) 56.5% William T. Longe (D) 43.5% |
| Pennsylvania 22 | John P. Saylor | Republican | 1949.0 | Re-elected | John P. Saylor (R) 51.9% Robert S. Glass (D) 48.1% |
| Pennsylvania 23 | Leon H. Gavin | Republican | 1942.0 | Re-elected | Leon H. Gavin (R) 61.9% Fred C. Barr (D) 38.1% |
| Pennsylvania 25 | Louis E. Graham | Republican | 1938.0 | Lost re-election Democratic gain | Frank M. Clark (D) 53.5% Louis E. Graham (R) 46.5% |
| Pennsylvania 26 | Thomas E. Morgan | Democratic | 1944.0 | Re-elected | Thomas E. Morgan (D) 65.3% Branko Stupar (R) 34.7% |
Question:
What is the incumbent for pennsylvania 15
Answer:
Francis E. Walter