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

int main()
{
    string s = "Have a nice day";
    string s2, s3, s4;

    s2 = s;
    s3 = "Hey";
    s4 = '!';

    cout << s3[1] << endl;
    s3[1] = 'a';
    cout << s3[1] << endl << endl;

    s2 += s4;
    cout << s2 << endl;
    s2 += '*';
    cout << s2 << endl << endl;

    cout << s3 + s4 << endl;
    cout << s3 + " you" << endl;
    cout << "you " + s3 << endl;
    cout << s3 + '?' << endl;
    cout << '?' + s3 << endl;
}