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

using ll = long long;
#define rep(i, n) for(int i = 0; i < n; i++)

int main() {
	string s;
	cin >> s;
	ll ans = atoi(s.c_str());
	int sz = s.size();
	rep(i, sz) {
		for(int j = i + 1; j < sz; j++) {
			string t = s;
			swap(t[i], t[j]);
			ll a = atoi(t.c_str());
			ans = max(ans, a);
		}
	}
	cout << ans << endl;
}