#include <bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i,n) for(int i = 0; i < (int)(n); ++i)
#define DEBUG(x) cerr << #x << " = " << x << endl
int memo[1 << 14];
string S;
int to_int(int i, int j, int k) {
  return 100 * (S[i] - '0') + 10 * (S[j] - '0') + (S[k] - '0');
}
int solve(int used) {
  int &res = memo[used];
  if(res != -1) return res;
  res = 0;
  for(int i = 0; i < (int)S.size(); ++i) {
    if((used >> i) & 1) continue;
    for(int j = i + 1; j < (int)S.size(); ++j) {
      if((used >> j) & 1) continue;
      if(S[i] == S[j]) {
        for(int k = 0; k < i; ++k) {
          if((used >> k) & 1) continue;
          if(S[k] != '0' && S[k] != S[i]) {
            res = max(res, to_int(k, i, j) + solve(used | (1 << i) | (1 << j) | (1 << k)));
          }
        }
      }
    }
  }
  return res;
}
signed main() {
  ios::sync_with_stdio(false);
  cin >> S;
  memset(memo, -1, sizeof(memo));
  cout << solve(0) << endl;
}