#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
//#define int long long
using namespace std;
typedef long long ll;

string N;

//numから取れる最大の和
int rec(string num) {
	//printf("num = %s\n", num.c_str());
	if (num.length() < 3) return 0;
	int res = 0;
	for (int i=0; i<num.length(); i++) {
		for (int j=i+1; j<num.length(); j++) {
			for (int k=j+1; k<num.length(); k++) {
				if (num[i] != num[j] && num[j] == num[k]) {
					string next = "";
					rep(l,num.length()) if (l != i && l != j && l != k) next += num[l];
					res = max(res, 100*(num[i]-'0') + 10*(num[j]-'0') + (num[k]-'0') + rec(next));
				}
			}
		}
	}
	return res;
}

signed main()
{
	cin >> N;
	cout << rec(N) << endl;
}