#include<iostream>
#include<algorithm>
#include<string>
#include<sstream>
using namespace std;

int to(string s)
{
	stringstream ss;
	ss<<s;
	int t;
	ss>>t;
	return t;
}

int n;
int ans=0;
string s;

int main()
{
	cin>>s;
	n=s.size();
	for(int i=0;i<n;i++)
	{
		for(int j=i+1;j<n;j++)
		{
			swap(s[i],s[j]);
			ans=max(ans,to(s));
			swap(s[i],s[j]);
		}
	}
	cout<<ans<<endl;
	return 0;
}