def read_seq_file(filename):
    """Reads data from sequence alignment test file.
    
    Args:
        filename (str): The file containing the edge list.
      
    Returns:
        str: The first sequence of characters.
        str: The second sequence of characters.
        int: The cost per gap in a sequence.
        int: The cost per mismatch in a sequence.
    """
    with open(filename, 'r') as f:
        next(f) # Skip first line
        cost_gap, cost_mismatch = next(f).strip().split()
        cost_gap, cost_mismatch = int(cost_gap), int(cost_mismatch)
        seq_x = next(f).strip()
        seq_y = next(f).strip()
        return seq_x, seq_y, cost_gap, cost_mismatch