What's the sum of the population for the place simplified with an area smaller than 2,879?
CREATE TABLE table_name_68 (
    population INTEGER,
    simplified VARCHAR,
    area VARCHAR
)
SELECT SUM(population) FROM table_name_68 WHERE simplified = "上杭县" AND area < 2 OFFSET 879
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: What's the sum of the population for the place simplified with an area smaller than 2,879? ### Input: CREATE TABLE table_name_68 (
    population INTEGER,
    simplified VARCHAR,
    area VARCHAR
) ### Response: SELECT SUM(population) FROM table_name_68 WHERE simplified = "上杭县" AND area < 2 OFFSET 879