#include "bits/stdc++.h"
using namespace std;

int main() {
string a,n;

	cin>>n;
	vector<int> c(n.length());
	vector<int> d(n.length());
	a=n;
	for (int i = 0; i < n.length(); ++i) {
		c[i]=n[i]-'0';
		d[i]=n[i]-'0';

	}
	sort(c.begin(),c.end(),greater<int>());
for (int i = 0; i < n.length(); ++i) {
	if(c[i]!=d[i]){
		for(int j=n.length()-1;j>=0;j--){
			if(d[j]==c[i]){
				swap(d[i],d[j]);
				for(int k=0;k<n.length();k++){
					cout<<d[k];
				}
				cout<<endl;
				return 0;
			}
		}
	}
}
for(int k=0;k<n.length();k++){
	cout<<d[k];
}
cout<<endl;
}