user: Question: What is the earliest year where the result of the election was a Retired Republican hold?
Columns: ['District', 'Incumbent', 'Party', 'First elected', 'Result', 'Candidates']
Types: ['text', 'text', 'text', 'real', 'text', 'text']
Sample row: ['Pennsylvania 1', 'Thomas Foglietta', 'Democratic', 1980.0, 'Re-elected', 'Thomas Foglietta (D) 87.50% James Cella (R) 12.49%']
SQL:

assistant: SELECT MIN("First elected") FROM "Table" WHERE "Result" = 'Retired Republican hold';