user: Question: Who is the lead for the team with Christina Haller as alternate?
Columns: ['Nation', 'Skip', 'Third', 'Second', 'Lead', 'Alternate']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Czech Republic', 'Katerina Urbanova', 'Lenka Cernovska', 'Jana Safarikova', 'Jana Simmerova', 'Zuzana Hajkova']
SQL:

assistant: SELECT "Lead" FROM "Table" WHERE "Alternate" = 'Christina Haller';