Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE grants (grant_amount VARCHAR, grant_end_date INTEGER)
TABLE: CREATE TABLE Grants (grant_amount VARCHAR, grant_id VARCHAR)
TABLE: CREATE TABLE Documents (grant_id VARCHAR, sent_date INTEGER)

### Question ###
What are the distinct grant amount for the grants where the documents were sent before '1986-08-26 20:49:27' and grant were ended after '1989-03-16 18:27:16'?

### Accurate SQL ###

SELECT T1.grant_amount FROM Grants AS T1 JOIN Documents AS T2 ON T1.grant_id = T2.grant_id WHERE T2.sent_date < '1986-08-26 20:49:27' INTERSECT SELECT grant_amount FROM grants WHERE grant_end_date > '1989-03-16 18:27:16'