#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <complex>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <sstream>
#include <fstream>

using namespace std;
#define REP(i, n) for (int (i) = 0; (i) < (n); (i)++)
#define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++)
#define RREP(i, a) for(int (i) = (a) - 1; (i) >= 0; (i)--)
#define FORR(i, a, b) for(int (i) = (a) - 1; (i) >= (b); (i)--)
#define DEBUG(C) cerr << #C << " = " << C << endl;
using LL = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<LL>;
using VVL = vector<VL>;
using VD = vector<double>;
using VVD = vector<VD>;
using PII = pair<int, int>;
using PDD = pair<double, double>;
using PLL = pair<LL, LL>;
using VPII = vector<PII>;
#define ALL(a) begin((a)), end((a))
#define RALL(a) rbegin((a)), rend((a))
#define SORT(a) sort(ALL((a)))
#define RSORT(a) sort(RALL((a)))
#define REVERSE(a) reverse(ALL((a)))
#define MP make_pair
#define FORE(a, b) for (auto &&a : (b))
#define FIND(s, e) ((s).find(e) != (s).end())
#define EB emplace_back

const int INF = 1e9;
const int MOD = INF + 7;
const LL LLINF = 1e18;

LL dfs(string s, LL num) {
    if (s.length() < 3) return num;
    LL res = 0;
    REP(i, s.length()) {
        FOR(j, i + 1, s.length()) {
            FOR(k, j + 1, s.length()) {
                if (s[i] != '0' && s[i] != s[j] && s[j] == s[k]) {
                    auto sbuf = s;
                    LL n = (s[i] - '0') * 100 + (s[j] - '0') * 10 + (s[k] - '0');
                    sbuf.erase(sbuf.begin() + i);
                    sbuf.erase(sbuf.begin() + j - 1);
                    sbuf.erase(sbuf.begin() + k - 2);
                    res = max(res, dfs(sbuf, n));
                }
            }
        }
    }
    return res + num;
}

int main(void) {
    string N; cin >> N;
    cout << dfs(N, 0LL) << endl;
}