#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
namespace __gnu_pbds{
          typedef tree<int,
                       null_type,
                       less_equal<int>,
                       rb_tree_tag,
                       tree_order_statistics_node_update> ordered_set;
}
using namespace __gnu_pbds;






void Insert(ordered_set &s,int x){ //this function inserts one more occurrence of (x) into the set.

     s.insert(x);

}


bool Exist(ordered_set &s,int x){ //this function checks weather the value (x) exists in the set or not.

     if((s.upper_bound(x))==s.end()){
        return 0;
     }
     return ((*s.upper_bound(x))==x);

}


void Erase(ordered_set &s,int x){ //this function erases one occurrence of the value (x).

     if(Exist(s,x)){
        s.erase(s.upper_bound(x));
     }

}


int FirstIdx(ordered_set &s,int x){ //this function returns the first index of the value (x)..(0 indexing).

    if(!Exist(s,x)){
        return -1;
    }
    return (s.order_of_key(x));

}


int Value(ordered_set &s,int idx){ //this function returns the value at the index (idx)..(0 indexing).

   return (*s.find_by_order(idx));

}


int LastIdx(ordered_set &s,int x){ //this function returns the last index of the value (x)..(0 indexing).

    if(!Exist(s,x)){
        return -1;
    }
    if(Value(s,(int)s.size()-1)==x){
        return (int)(s.size())-1;
    }
    return FirstIdx(s,*s.lower_bound(x))-1;

}


int Count(ordered_set &s,int x){ //this function returns the number of occurrences of the value (x).

     if(!Exist(s,x)){
        return 0;
     }
     return LastIdx(s,x)-FirstIdx(s,x)+1;

}


void Clear(ordered_set &s){ //this function clears all the elements from the set.

     s.clear();

}


int Size(ordered_set &s){ //this function returns the size of the set.

     return (int)(s.size());

}



int main(){


     /*

     *Please read the above functions and their descriptions.

     *If you want to change your multi ordered set data type,you should change almost everything in the above functions.

     */



     return 0;

}