from functools import lru_cache
import itertools

N = tuple(int(x) for x in list(input()))

@lru_cache(maxsize=None)
def rec(n):
    if len(n) < 2:
        return 0
    res = 0
    for selector in itertools.combinations(range(len(n)), 3):
        num = tuple(x for i, x in enumerate(n) if i in selector)
        cww = 0
        if num[0] and num[0] != num[1] == num[2]:
            cww = num[0] * 100 + num[1] * 10 + num[2]

        remains = tuple(x for i, x in enumerate(n) if i not in selector)
        res = max(res, cww + rec(remains))
    return res


print(rec(N))