#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()

template<typename A, typename B> inline bool chmax(A &a, B b) { if (a<b) { a=b; return 1; } return 0; }
template<typename A, typename B> inline bool chmin(A &a, B b) { if (a>b) { a=b; return 1; } return 0; }

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<int, pii> P;

const ll INF = 1ll<<29;
const ll MOD = 1000000007;
const double EPS  = 1e-10;

string n;
int dp[1<<13];

int main() {
	cin >> n;
	REP(i, n.size()) n[i] -= '0';
	
	memset(dp, -1, sizeof(dp));
	dp[0] = 0;
	
	REP(i, 1<<n.size()) {
		if (dp[i] == -1) continue;
		REP(j, n.size()) if (!(i >> j & 1) && n[j] != 0) {
			FOR(k, j + 1, n.size()) if (!(i >> k & 1) && n[j] != n[k]) {
				FOR(l, k + 1, n.size()) if (!(i >> l & 1) && n[k] == n[l]) {
					chmax(dp[i | 1<<j | 1<<k | 1<<l], dp[i] + n[j] * 100 + n[k] * 10 + n[l]);
				}
			}
		}
	}
	
	int ans = 0;
	REP(i, 1<<n.size()) chmax(ans, dp[i]);
	cout << ans << endl;
	
	return 0;
}