#include <bits/stdc++.h>

using ll = long long;
using ld = long double;
using namespace std;

vector<ll> z1;
ll w = 0;
ll sol = 0;
ll x;
vector<bool> hp;

void solve(ll pos, ll n)
{
    if (pos == n)
    {
        if (w > x && (sol == 0 || sol > w))
        {
            sol = w;
        }
        w = 0;
    }
    for (int i = 0; i < z1.size(); i++)
    {
        if (hp.at(i) == false)
        {
            hp.at(i) = true;
            w = w * 10 + z1.at(i);
            solve(pos + 1, n);
            hp.at(i) = false;
        }
    }
}

int main()
{

    cin >> x;

    ll ax;
    ax = x;
    while (ax > 0)
    {
        z1.push_back(ax % 10);
        hp.push_back(false);
        ax = ax / 10;
    }

    solve(0, z1.size());

    cout << sol << endl;
    return 0;
}