user: Question: When did Chang Myon (장면) leave office?
Columns: ['President', 'Vice', 'Romanized (Hangul)', 'Took office', 'Left office', 'Political party']
Types: ['text', 'real', 'text', 'text', 'text', 'text']
Sample row: ['Syngman Rhee', 1.0, 'Yi Si-yeong (이시영)', '24 July 1948', '9 May 1951 (Resign)', 'Korea Democratic Party']
SQL:

assistant: SELECT "Left office" FROM "Table" WHERE "Romanized (Hangul)" = 'Chang Myon (장면)';