How many different clerks have served the customer with the address uFTe2u518et8Q8UC?
clerk who have served the customer refers to o_clerk

SELECT COUNT(T1.o_clerk) FROM orders AS T1 INNER JOIN customer AS T2 ON T1.o_custkey = T2.c_custkey WHERE T2.c_address = 'uFTe2u518et8Q8UC'