import re

def process_file(file_path):
    with open(file_path, 'r',encoding='utf-8') as file:
        for line in file:
            modified_line = re.sub(r'\b(?:[A-Z]+\w*[a-z]+\w*|[a-z]+\w*[A-Z]+\w*)\b', lambda match: match.group(0).swapcase(), line)
            print(modified_line, end='')

file_path = 'polish_wiki_excerpt.exp'
process_file(file_path)