#define _USE_MATH_DEFINES
#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string>
#include<iostream>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include<queue>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include <sstream>
#include<iomanip>
#include <ctype.h>
#include <fstream>
#include <cassert>
//#include <bits/stdc++.h>
using namespace std;

//#include<bits/stdc++.h>
int d(string p) {
	int n = p.size();
	int s = 0;
	for (int i = 0; i < n; i++) {
		for (int j = i + 1; j < n; j++) {
			for (int k = j + 1; k < n; k++) {
				if (p[i] != '0'&&p[i] != p[j] && p[j] == p[k]) {
					int r = (p[i]) * 100 + (p[j] ) * 10 + p[k]-'0'*111;
					string x = p;
					x.erase(i, 1);
					x.erase(j-1, 1);
					x.erase(k-2, 1);
					s = max( d(x)+r, s);
				}
			}
		}
		return s;
	}

}

	
int main() {
	string p;
	
	cin >> p;
	cout << d(p) << endl;

	return 0;
}