user: Question: Name the number of candidates for  Samuel D. Ingham
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Pennsylvania 4', 'Hugh Glasgow', 'Democratic-Republican', 1812.0, 'Retired Democratic-Republican hold', 'Jacob Spangler (DR) 67.1% Jacob Hay (F) 32.9%']
SQL:

assistant: SELECT COUNT("Candidates") FROM "Table" WHERE "Incumbent" = 'Samuel D. Ingham';