#include <iostream>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using namespace std;

template<class T>
constexpr T INF = ::numeric_limits<T>::max() / 32 * 15 + 208;

int main() {
    string s;
    cin >> s;
    int n = s.size();
    int ans = 0;
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n; ++j) {
            string t = s;
            swap(t[i], t[j]);
            ans = max(ans, stoi(t));
        }
    }
    cout << ans << "\n";
    return 0;
}