#include <iostream>
#include <string>

using namespace std;

string N;

int get_change_partner(int index) {
  char max = N[index];
  for (int i=index+1;i<N.length();i++) {
    max = (N[i] > max) ? N[i] : max;
  }
  if (max > N[index]) {
    for (int i=N.length()-1;i>index;i--) {
      if (N[i] == max) {
        return i;
      }
    }
  }
  return -1;
}

int main(){
  cin >> N;
  for (int i=0;i<N.length();i++) {
    int change_partner = get_change_partner(i);
    if (change_partner != -1) {
      char tmp = N[i];
      N[i] = N[change_partner];
      N[change_partner] = tmp;
      break;
    }
  }
  cout << N << endl;
}