#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <utility>

using namespace std;

vector<int> digits;
vector<int> orders;
int n_digits;

int get_num(int a, int b) {
	auto tmp = digits;
	swap(tmp[a], tmp[b]);
	int num = 0;
	for (int i = 0; i < n_digits; i++) {
		num += tmp[i] * orders[i];
	}
	return num;
}

int main() {
	int n;
	cin >> n;

	int ans = n;
	while (n > 0) {
		digits.push_back(n % 10);
		n /= 10;
	}

	n_digits = digits.size();
	orders.assign(n_digits, 0);
	orders[0] = 1;
	for (int i = 1; i < n_digits; i++) {
		orders[i] = 10 * orders[i - 1];
	}

	for (int i = 0; i < n_digits; i++) {
		for (int j = i + 1; j < n_digits; j++) {
			ans = max(ans, get_num(i, j));
		}
	}

	cout << ans << endl;
	return 0;
}