#include <iostream>
#include <vector>
using namespace std;




class DNA{
    private:
    struct lanac{

        int pos;
        string lanac;
    };

    vector<lanac> molekula;
    int size;


    public:
    void print(std::ostream& o) const{
        for(auto it=molekula.begin(); it!=molekula.end(); ++it){
            o << it->pos << "-" << it->pos+(it->lanac).size()<< " " << it->lanac << "\n";
        }

        o << "\n";
    }

    string toString() const {

                 string str;


         for(auto i=0; i<molekula.size(); ++i){
                         if(i>=1){
             if( (molekula[i].pos-1) > (molekula[i-1].pos+molekula[i-1].lanac.size()) ) str+=string(((molekula[i].pos) - (molekula[i-1].pos+molekula[i-1].lanac.size())),'x');
             }
             str+=molekula[i].lanac;

         }

         return str;

    }

     void print(std::ostream& o, int p, int len) const{

        string str=toString();

         o << p << "-" << len << " ";
         for(auto j=p; j<len; ++j)
            if(str[j]!='x') o << str[j];



    }




     void insert(int pos, std::string l){

        // molekula.push_back(lanac{pos, l});

      string stringToChange = toString();

       int size = stringToChange.size();
        molekula.clear();


         if(pos >= size) {
             stringToChange += string((pos-stringToChange.size()), 'x');
             stringToChange += l;
         } else {
             for (int i = pos, j = 0; j < l.size(); ++i, ++j) {
                 if (i < size) {
                     stringToChange[i] = l[j];
                 } else {
                     stringToChange.push_back(l[j]);
                 }
             }
         }


         toMolekula(stringToChange);
     }

     void toMolekula(string& lanacToChange) {
         for (int i = 0; i < lanacToChange.size(); ++i) {
          if (lanacToChange[i] != 'x') {
                string noviLanac = "";
                int position = i;
                while(lanacToChange[i] != 'x' && i < lanacToChange.size()) {
                    noviLanac += lanacToChange[i++];
                }
                molekula.push_back(lanac{position, noviLanac});
            }
        }
     }


    int remove(int pos, int len) {
        string lanacToChange = toString();
        if (pos >= lanacToChange.size()) {
            return 0;
        }

        int ret_number = 0;
        for (int i = pos; i <= len; ++i) {
            if (lanacToChange[i] != 'x') {
                lanacToChange[i] = 'x';
                ++ret_number;
            }
        }

        molekula.clear();

        toMolekula(lanacToChange);

        return ret_number;
    }
};


int main(){

    DNA mol;

    mol.insert(0,"ATCG");
    mol.insert(8, "TGCA");
    mol.print(std::cout);
    mol.insert(10, "TTTT");
    mol.remove(1, 2);
    mol.print(cout);

    return 0;
}