def main():
    x = input() + "$"

    ss = []
    s = ""
    len = 0
    maxlen = 0
    first = True

    for c in x:
        if c == 'ｗ':
            len += 1

        else:
            if not first and len > 0:
                if len > maxlen:
                    maxlen = len
                    ss = []

                if len == maxlen:
                    ss.append(s)

                s = ""

            len = 0
            s += c
            first = False

    for s in ss:
        print(s)


if __name__ == "__main__":
    main()