void insertAtLine(int lineNumber,string line)
 {
  ofstream myfile("C:\Users\test\Music\myfile.txt");

   int counter=0;
   if(myfile.is_open())
   {
    string str;
    do{
        getline(cin, str);
        if(counter == lineNumber)
        {
              myfile<<line<< endl;
        }
        counter++;

    }while(str!="");
    myfile.close();
}
else cerr<<"Unable to open file";

}