#include<iostream>
#include<vector>
#include<string>
#include<cstring>
#include<algorithm>
#include<map>
#include<set>

using namespace std;
int N[15];
int dp[1<<15];
int n;

bool isPop(int state, int i) {
	return (state>>i)&1;
}
bool isCww(int x) {
	return (x%10) == ((x/10)%10);
}

int dfs(int state) {
	int& ret = dp[state];
	if (ret >= 0) return ret;
	ret = 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 (!isPop(state, i) && !isPop(state, j) && !isPop(state, k)) {
					if (N[j] != N[k]) continue;
					if (N[i] == N[j]) continue;
					if (!N[i]) continue;
					int tmp = N[i]*100 + N[j]*10 + N[k];
					ret = max(ret, tmp+dfs(state^(1<<i)^(1<<j)^(1<<k)));
				}
			}
		}
	}
	return ret;
}

int main() {
	string S;
	cin >> S;
	n = S.size();
	for (int i = 0; i < n; i++)
		N[i] = S[i]-'0';
	memset(dp, -1, sizeof(dp));
	cout << dfs(0) << endl;
	return 0;
}