string = input() string = string.lower() lst = [] dic = {} cur = None cur_l = 0 for ch in string: if not ch.isalpha(): continue if cur is None: cur = ch cur_l = 1 continue if cur == ch: cur_l += 1 else: if cur in dic: dic[cur] += cur_l if cur_l == 1: dic[cur] = 0 else: lst.append((cur, cur_l)) cur = ch cur_l = 1 if cur in dic: dic[cur] += cur_l if cur_l == 1: dic[cur] = 0 else: lst.append((cur, cur_l)) for k, v in dic.items(): lst.append((k, v)) lst.sort(key=lambda x: (-x[1], x[0])) ans = "".join(f"{x[0]}{x[1]}" for x in lst) print(ans)