## https://yukicoder.me/problems/no/806

def main():
    A = input()

    if len(A) == 1:
        print(A)
        return

    answer = 0
    forward_words = []
    backward_words = []
    for i in range(len(A)):

        a = A[i]
        forward_words.append(a)
        backward_words.append(a)

        # 偶数
        backward_words.reverse()
        word = forward_words + backward_words
        backward_words.reverse()
        word = "".join(word)
        if word.startswith(A):
            print(word)
            return

        # 奇数
        if i + 1 < len(A):
            backward_words.reverse()
            word = forward_words + [A[i + 1]] + backward_words
            backward_words.reverse()
            word = "".join(word)
            if word.startswith(A):
                print(word)
                return
    print(answer)

        



                




if __name__ == "__main__":
    main()