#include <iostream>
#include <vector>
#include <string>
using namespace std;

int main() {
    int N;
    cin >> N;

    string Ns = to_string(N);
    for (int i = 0; i < (int)Ns.size(); ++i) {
        int max = Ns[i];
        int idx = i;
        for (int j = (int)Ns.size() - 1; j >= i + 1; --j) {
            if (max < Ns[j]) {
                max = Ns[j];
                idx = j;
            }
        }
        if (idx != i) {
            swap(Ns[i], Ns[idx]);
            break;
        }
    }
    
    cout << Ns << endl;
}