#include <iostream>

using namespace std;

int main() {
    for (int i{2}; i < 16; ++i) {
        if (i % 3 == 0) {
            cout << i << endl;
        }
    }

    cout << endl << "Drugi sposob:\n";
    int i{ 3 };
    while (i < 16) {
        cout << i << endl;
        i += 3;
    }

    return 0;
}