#include <iostream>
using namespace std;

int afterMaxId[20];

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

	int size = N.size();
	afterMaxId[size-1] = size-1;

	for(int i=size-2;i>=0;i--){
		int id = afterMaxId[i+1];
		if(N[i] > N[id]){
			id = i;
		}
		afterMaxId[i] = id;
	}

	for(int i=0;i<size;i++){
		int id = afterMaxId[i];
		if(N[id] > N[i]){
			swap(N[id], N[i]);
			break;
		}
	}

	cout << N << endl;
	return 0;
}