#include <string>
#include <algorithm>
using namespace std;

class LargestSubsequence {
public:
    string getLargest(string s) {
        string res;
        for (auto base = s.begin(); base != s.end(); ++base) {
            auto it = max_element(base, s.end());
            res += *it;
            base = it;
        }
        return res;
    }
};