Table:
ball signed by a famous football player	$179.00

photograph signed by a famous race car driver	$843.00

DVD signed by a famous comedian	$161.00

photograph signed by a famous singer	$605.00

painting signed by a famous artist	$998.00

This image illustrates a table. Find the cell at the intersection of the 4th row and the 1st column, return its content. The target cell value should be presented in the JSON format of {"row_id":"m", "column_id":"n", "cell_value":"<Corresponding Cell Value>"}, e.g., {"row_id":"10", "column_id":"3", "cell_value":"District"}.

The target cell value in the 4th row and the 1st column is {"row_id":"4", "column_id":"1", "cell_value":"photograph signed by a famous singer"}.