#include <iostream>

#include <string>

#include <vector>

#include <iostream>

using std::cout;

using std::cin;

using std::endl;

using std::vector;

using namespace std;

int main()

{

    string s = "hell";

    string w = "worl!";

    s = s + w; //s +=w;

    for (int ii = ; ii != s.size(); ii++)

    {

        cout << ii << " " << s[ii];

    }

    cout << endl;

    string::const_iterator cii;

    int ii = ;

        for (cii = s.begin(); cii != s.end(); cii++)

    {

        cout << ii++ << " " << *cii << endl;

    }

    vector<double> student_marks;

    int num_students;

    cout << "Number of students: " << endl;

    cin >> num_students;    

    student_marks.resize(num_students);

    for (vector<double>::size_type i = ; i < num_students; i++)

    {

        cout << "Enter marks for student #" << i +

            << ": " << endl;

        cin >> student_marks[i];

    }

    cout << endl;

    for (vector<double>::iterator it = student_marks.begin();

        it != student_marks.end(); it++)

    {

        cout << *it << endl;

    }

    return ;

}