#include <cstddef>
#include <iostream>

int main() {
    int values[]{2, 4, 6};
    int* first{values};
    int* last{values + 3};
    const std::ptrdiff_t forward{last - first};
    const std::ptrdiff_t backward{first - last};
    std::cout << forward << ' ' << backward << '\n';
    std::cout << *first << ' ' << *(first + 1) << ' ' << *(last - 1) << '\n';
    return 0;
}