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

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#define dump(val) cerr << __LINE__ << ":\t" << #val << " = " << (val) << endl

using namespace std;

typedef long long int lli;

template<typename T>
vector<T> make_v(size_t a, T b) {
    return vector<T>(a, b);
}

template<typename... Ts>
auto make_v(size_t a, Ts... ts) {
    return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

int main() {
    string s;
    cin >> s;
    set<string> st;
    st.insert(s);
    REP(i, 0, s.size()) {
        REP(j, i + 1, s.size()) {
            string tmp = s;
            swap(tmp[i], tmp[j]);
            st.insert(tmp);
        }
    }
    cout << *rbegin(st) << endl;
    return 0;
}