Write SQL query to solve given problem: How many French customers does Gerard Hernandez take care of?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT COUNT(t1.customerNumber) FROM customers AS t1 INNER JOIN employees AS t2 ON t1.salesRepEmployeeNumber = t2.employeeNumber WHERE t1.country = 'France' AND t2.firstName = 'Gerard' AND t2.lastName = 'Hernandez'