#include <iostream>
#include <string>
int main()
{
    using namespace std;

    //1й пункт
    string s1 = "Computer programming (often shortened to programming) is a process";
    for (int i = 2; i < s1.size(); i = i + 3)
        cout << s1[i];
    cout << endl;

    //2й пункт
    string s2 = "Programming involves activities such as analysis, developing understanding";
    for (int i = 1; i < s2.size(); i = i + 2)
        if (s2[i] != 'a' && s2[i] != 'b')
            s2[i] = 'a';
        else
            s2[i] = 'c';
    cout << s2 << endl;

    return 0;
}