#include <algorithm>

namespace Game {
    template<typename T>
    class Coord {
    public:
        typedef T value_type;
        T row;
        T col;

        Coord(T in_row = T(), T in_col = T()) : row(in_row), col(in_col) {}
    };

    template<typename T>
    T dist(const Coord<T> &field, const Coord<T> &cell1, const Coord<T> &cell2) {
        Coord<T> from(cell1), to(cell2);
        if (from.col > to.col) {
            std::swap(from.col, to.col);
            std::swap(from.row, to.row);
        }

        T answer = 0;
        for (auto i = from.col; i <= to.col; ++i) {
            if (from.row < to.row) {
                if (from.col % 2 == 0) {
                    ++from.row;
                }
            } else if (from.row > to.row) {
                if (from.col % 2 != 0) {
                    --from.row;
                }
            }
            ++answer;
        }
        return answer + std::abs(from.row - to.row);
    }
}