Translate the following question to SQL: List the distinct police forces of counties whose location is not on east side.

Schema: CREATE TABLE county_public_safety (
    County_ID INT   PRIMARY KEY,
    Name TEXT,
    Population INT,
    Police_officers INT,
    Residents_per_officer INT,
    Case_burden INT,
    Crime_rate REAL,
    Police_force TEXT,
    Location TEXT,
    UNIQUE (County_ID)
);

CREATE TABLE city (
    City_ID INT   PRIMARY KEY,
    County_ID INT,
    Name TEXT,
    White REAL,
    Black REAL,
    Amerindian REAL,
    Asian REAL,
    Multiracial REAL,
    Hispanic REAL,
    UNIQUE (City_ID),
    FOREIGN KEY (County_ID) REFERENCES county_public_safety(County_ID)
);
user
SELECT DISTINCT Police_force FROM county_public_safety WHERE LOCATION != "East"
assistant