def search_in_file(keyword: str) -> list[str]:
    result: list[str] = []
    with open(file="example.txt", mode="r", encoding="utf-8") as file:
        lines: list[str] = file.readlines()
        for line in lines:
            index: int = 0
            symbol_id: int = 0
            line_lower: str = line.lower()
            while symbol_id != len(line):
                if line_lower[symbol_id] == keyword[index]:
                    index += 1
                    if index == len(keyword):
                        result.append(line)
                        break
                else:
                    index = 0
                symbol_id += 1
    return result


def search_in_file_t(keyword: str) -> None:
    with open(file="example.txt", mode="r", encoding="utf-8") as file:
        for line in file:
            if keyword.lower() in line.lower():
                print(line.strip())


search_in_file_t("без")
print(search_in_file("без"))