#include <algorithm> #include <cmath> #include <cstdio> #include <cstdlib> #include <functional> #include <iostream> #include <iterator> #include <list> #include <map> #include <queue> #include <set> #include <sstream> #include <stack> #include <string> #include <utility> #include <valarray> #include <vector> #define N 1000 #define MOD 1000000007 #define pe(str) return cout<<(str)<<endl,0 #define px(str) {cout<<str<<endl;exit(0);} #define re(i,n) for(int i=0;i<(n);i++) #define rep(i,a,b) for(int i=(a);i<(b);i++) #define fe(i,n,f) for_each(i,n,f) #define bw(a,b,c) (((a)<=(b))&&((b)<=(c))) using namespace std; typedef long long ll; typedef unsigned long long ull; typedef long double ld; int main(void){ string s; cin>>s; sort(s.begin(),s.end(),greater<char>() ); cout<<s<<endl; return 0; }