#include <iostream>
#include <string>
#include <algorithm>
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
int dp[1000][4400] = { 0 };
int main() {
    string s;
    cin >> s;
    int n = s.size();
    vector<pair<int, int>> vec;
    for (int i = 0; i < n; i++) {
        for (int j = i + 1; j < n; j++) {
            for (int k = j + 1; k < n; k++) {
                if (s[j] == s[k] && s[i] != s[j]) {
                    bitset<12> bit;
                    bit[i] = 1;
                    bit[j] = 1;
                    bit[k] = 1;
                    string s1 = "";
                    s1 += s[i];
                    s1 += s[j];
                    s1 += s[k];
                    int x = stoi(s1);
                    vec.emplace_back(make_pair(bit.to_ulong(), x));
                }
            }
        }
    }
    for (int i = 0; i < vec.size(); i++) {
        for (int j = 0; j < (1 << n); j++) {
            bool b = true;
            bitset<12> bit = vec[i].first, bit1 = j;
            for (int i = 0; i < 12; i++) {
                if (bit[i] == 1 && bit1[i] == 1) {
                    b = false;
                }
            }
            if (b) {
                dp[i + 1][j | vec[i].first] = max(dp[i + 1][j | vec[i].first], dp[i][j] + vec[i].second);
            }
            dp[i + 1][j] = max(dp[i + 1][j], dp[i][j]);
        }
    }
    int ans = 0;
    for (int i = 0; i < (1 << n); i++) {
        if (ans < dp[vec.size()][i]) {
            ans = dp[vec.size()][i];
        }
    }
    cout << ans << endl;
}