Write SQL query to solve given problem: Among the independent countries whose type of government is republic, what is the biggest number of deserts they have?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT COUNT(T3.Desert) FROM country AS T1 INNER JOIN politics AS T2 ON T1.Code = T2.Country INNER JOIN geo_desert AS T3 ON T3.Country = T2.Country WHERE T2.Government = 'republic'