What is the total for the first exercise and has 18 as the second exercise?
CREATE TABLE table_12404 (
    "Place" real,
    "Nation" text,
    "First Exercise" real,
    "Second Exercise" real,
    "Total" real
)
SELECT SUM("First Exercise") FROM table_12404 WHERE "Second Exercise" = '18'
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 is the total for the first exercise and has 18 as the second exercise? ### Input: CREATE TABLE table_12404 (
    "Place" real,
    "Nation" text,
    "First Exercise" real,
    "Second Exercise" real,
    "Total" real
) ### Response: SELECT SUM("First Exercise") FROM table_12404 WHERE "Second Exercise" = '18'