#include "bits/stdc++.h" using namespace std; using Graph = vector>; typedef long long ll; typedef pair P; #define rep(i,n) for (ll i = 0; i < (n); ++i) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() const long long mod = 1e9 + 7; ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } ll lcm(ll a, ll b) { return a / gcd(a, b) * b; } ll powMod(ll n, ll k, ll m) { if (k == 0) { return 1; } else if (k % 2 == 1) { return powMod(n, k - 1, m) * n % m; } else { ll t = powMod(n, k / 2, m); return t * t % m; } } int main() { string s; cin >> s; vector v; rep(i, s.size()) { rep(j, s.size()) { string t = s; swap(t[i],t[j]); v.push_back(t); } } sort(rall(v)); cout << v[0] << endl; }