user: Question: What is the rad number for the Dead end in rank 22?
Columns: ['Rank', 'Height', 'Name', 'Road number', 'Type']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['1', '670 m', 'Cairnwell Pass', 'A93', 'Pass']
SQL:

assistant: SELECT "Road number" FROM "Table" WHERE "Type" = 'Dead end' AND "Rank" = '22';