include<bits/stdc++.h>

using namespace std; int main(){

string s;
getline(cin ,s);
string b;
for (int i = 0; i < s.length(); i++){
    if (s[i] % 3 == 0){
        continue;
    } b = b+s[i];
}
sort(b.begin(),b.end());
cout << b;
return 0;

}