How many combination classifications have the winner as Erik Zabel and a points classification as Alessandro Petacchi
CREATE TABLE table_19833 (
    "Stage" real,
    "Winner" text,
    "General classification" text,
    "Points classification" text,
    "Mountains classification" text,
    "Combination classification" text,
    "Team classification" text
)
SELECT COUNT("Combination classification") FROM table_19833 WHERE "Points classification" = 'Alessandro Petacchi' AND "Winner" = 'Erik Zabel'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: How many combination classifications have the winner as Erik Zabel and a points classification as Alessandro Petacchi ### Input: CREATE TABLE table_19833 (
    "Stage" real,
    "Winner" text,
    "General classification" text,
    "Points classification" text,
    "Mountains classification" text,
    "Combination classification" text,
    "Team classification" text
) ### Response: SELECT COUNT("Combination classification") FROM table_19833 WHERE "Points classification" = 'Alessandro Petacchi' AND "Winner" = 'Erik Zabel'