#include <cstdio>
#include <algorithm>
#include <iostream>
#include <vector>
#include <string>
#include <typeinfo>
using namespace std;

vector<int> a;
int n;

int sol(int x,int y, int z,int box[15]){
  int tmp=0,res=0;
  int i,j,k;

  for(i=x;i<n;i++){
    //cout<<"a";
    for(j=i+1;j<n;j++){
      //cout<<"b";
      for(k=j+1;k<n;k++){
        //cout<<"c";
        if(a[i]!=0&&a[i]!=a[j]&&a[j]==a[k]&&box[i]!=1&&box[j]!=1&&box[k]!=1) {

          //cout<<"waro"<<endl;
          box[i]=box[j]=box[k]=1;
          tmp=sol(0,1,2,box)+a[i]*100+a[j]*11;
          box[i]=box[j]=box[k]=0;
          //res+=a[i]*100+a[j]*11;
          res=max(tmp,res);
        }
      }
    }
  }

  return res;
}

int main(void){
  
  int i,l,r,k,t,j,tmp;
  int N;
  int res=0;
  string s;
  int box[15];
  
  cin>>s;
  n=s.length();
  a.resize(n);

  for(i=0;i<15;i++) box[i]=0;
  for(i=0;i<n;i++){
    a[i]=s[i]-'0';
  }

  tmp=sol(0,1,2,box);
  cout<<tmp<<endl;
  return 0;
}