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 table_name_78 (april_14 VARCHAR, mar_3 VARCHAR, april_21 VARCHAR)

### Question ###
What is the April 14 rank when the Mar 3rd is nr, and the April 21 is 13?

### Accurate SQL ###

SELECT april_14 FROM table_name_78 WHERE mar_3 = "nr" AND april_21 = "13"