#include <bits/stdc++.h>
using namespace std;

#define REP(i,n) for(int i=0;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define INF 1<<29
#define LINF LLONG_MAX/3
#define MP make_pair
#define PB push_back
#define EB emplace_back
#define ALL(v) (v).begin(),(v).end()
#define all(v) ALL(v)
#define debug(x) cerr<<#x<<":"<<x<<endl
#define debug2(x,y) cerr<<#x<<","<<#y":"<<x<<","<<y<<endl
#define CININIT cin.tie(0),ios::sync_with_stdio(false)
template<typename T> ostream& operator<<(ostream& os,const vector<T>& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; }
template<typename T,typename U> ostream& operator<<(ostream& os,const pair<T,U>& p){ os << "(" << p.first << ","<< p.second <<")"; return os; }
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
ll gcd(ll a,ll b){ if(b==0) return a; else return gcd(b,a%b); }

constexpr ll mod = 1e9+7;
const int dx[]={1,0,-1,0} ,dy[] = {0,1,0,-1};

string s;
int n;

int dfs(const vector<bool>& use){
    int ret=0;
    for(int i=0;i<n;i++){
        if(s[i]=='0' or !use[i]) continue;
        int c = s[i]-'0';
        for(int j=i+1;j<n;j++) if(use[j] and s[i]!=s[j]){
            int w = s[j]-'0';
            for(int k=j+1;k<n;k++) if(use[k] and s[j]==s[k]){
                auto nv(use);
                nv[i]=false;
                nv[j]=false;
                nv[k]=false;
                int p=c*100+w*10+w;
                int tmp=dfs(nv);
                ret = max(ret,tmp+p);
            }
        }
    }
    return ret;
}

int main(){
    cin>>s;
    n=s.size();
    vector<bool> v(n,true);
    cout << dfs(v) << endl;
}