#!/usr/bin/env pypy3

import collections
import itertools
import sys


REC_LIMIT = 10000
UNDEF = -1


def is_cww(s):
    return len(s) == 3 and 0 != s[0] != s[1] == s[2]


def solve(n):
    dp = collections.defaultdict(lambda: UNDEF)

    def rec(x0):
        if dp[x0] != UNDEF:
            return dp[x0]
        score = 0
        for i, j, k in itertools.combinations(range(len(x0)), 3):
            y = x0[i] + x0[j] + x0[k]
            if not is_cww(y):
                continue
            x = x0[:i] + x0[j + 1:k] + x0[k + 1:]
            score = max(score, rec(x) + int(y))
        dp[x0] = score
        return score

    return rec(str(n))


def main():
    sys.setrecursionlimit(REC_LIMIT)
    n = int(input())
    print(solve(n))


if __name__ == '__main__':
    main()