What is the lowest cr number?
CREATE TABLE table_22640 (
    "HR no." text,
    "HR name" text,
    "CR no." real,
    "LMS no." real,
    "Built" text,
    "Works" text,
    "Withdrawn" text
)
SELECT MIN("CR no.") FROM table_22640
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 lowest cr number? ### Input: CREATE TABLE table_22640 (
    "HR no." text,
    "HR name" text,
    "CR no." real,
    "LMS no." real,
    "Built" text,
    "Works" text,
    "Withdrawn" text
) ### Response: SELECT MIN("CR no.") FROM table_22640