input: Write a python function to remove lines containing the word "deleted" from a text file and write the remaining lines to another file.
  assert remove_deleted_lines('input1.txt', 'output1.txt')==None
  assert remove_deleted_lines('input2.txt', 'output2.txt')==None
  assert remove_deleted_lines('input3.txt', 'output3.txt')==None
output: def remove_deleted_lines(input_file, output_file):
      with open(input_file, 'r') as infile, open(output_file, 'w') as outfile:
          for line in infile:
              if 'deleted' not in line:
                  outfile.write(line)