#include<bits/stdc++.h>

#define ALL(v) v.begin(), v.end()
typedef long long ll;



using namespace std;
int main() {
	string n,temp;
	int maxx = 0;
	cin >> n;
	
	maxx = stoi(n);

	for (int i = 0; i < n.length(); i++)
	{
		for (int j = 0; j < n.length(); j++)
		{
			temp = n;

			char a = n[i];
			char b = n[j];

			temp[i] = b;
			temp[j] = a;

			int tempI = stoi(temp);

			maxx = max(maxx, tempI);

		}
	}

	
	cout << maxx << endl;


}