def merge_the_tools(string: str, k: int):
    length: int = len(string)

    for i in range(0, length, k):
        result: list[str] = []
        for char in string[i : i + k]:
            if char not in result:
                result.append(char)

            print("".join(result))


if __name__ == "__main__":
    string, k = input(), int(input())
    merge_the_tools(string, k)