target, create a signature string for the row.\n c. Increment the count of the signature in the hashmap.\n d. Increment the column count for each black pixel.\n4. Initialize a result counter to 0.\n5. Iterate over the hashmap:\n a. If a signature count is target, iterate over the columns:\n i. If a column has target black pixels and the pixel at the current row is black, increment the result by target.\n6. Return the result.