#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <algorithm>
#include <sstream>
#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>

using namespace std;

int f(string s) {
	int ret = 0, dec = 1;
	for(int i = s.size() - 1; 0 <= i; i--) {
		ret += (int)(s[i] - '0') * dec;
		dec *= 10;
	}
	return ret;
}

int main() {

	string N;
	cin >> N;

	int ans = f(N);
	for (int i = 0; i < N.size() - 1; i++) {
		for (int j = i + 1; j < N.size(); j++) {
			string ts = N;
			char t;
			t = ts[i];
			ts[i] = ts[j];
			ts[j] = t;
			ans = max(ans, f(ts));
		}
	}

	cout << ans << endl;

	return 0;
}