#include <iostream>
#include <utility>
#include <vector>
#include <tuple>
#include <cstdint>
#include <queue>
#include <limits>

using namespace std;

// Type aliases
using i8  =  int8_t; using  u8 =  uint8_t;
using i16 = int16_t; using u16 = uint16_t;
using i32 = int32_t; using u32 = uint32_t;
using i64 = int64_t; using u64 = uint64_t;

template <class T> using V = vector<T>;

// Loops
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = (n) - 1; i >= 0; --i)
#define FOR(i, n, m) for (int i = (n); i < (m); ++i)
#define FORR(i, n, m) for (int i = (m) - 1; i >= (n); --i)

#define FORE(x, xs) for (auto &x: (xs))

// Utils for Tuple
namespace tuple_utils {
    template<size_t...> struct seq{};

    template<size_t N, size_t... Is>
    struct gen_seq : gen_seq<N - 1, N - 1, Is...>{};

    template<size_t... Is>
    struct gen_seq<0, Is...> : seq<Is...>{};

    template <class Tuple, size_t... Is>
    void read(istream &stream, Tuple &t, seq<Is...>) {
        static_cast<void>((int[]){0, (void(stream  >> get<Is>(t)), 0)...});
    }

    template<class Tuple, size_t... Is>
    void print(ostream& stream, Tuple const& t, seq<Is...>) {
        static_cast<void>((int[]){0, (void(stream << (Is == 0 ?  "" : ", ") << get<Is>(t)), 0)...});
    }

    template <size_t I, class F, class A, class... Elems>
    struct ForEach {
        void operator()(A &arg, tuple<Elems...> const& t) const {
            F()(arg, get<I>(t));
            ForEach<I - 1, F, A, Elems...>()(arg, t);
        };
        void operator()(A &arg, tuple<Elems...>& t) const {
            F()(arg, get<I>(t));
            ForEach<I - 1, F, A, Elems...>()(arg, t);
        };
    };
    template <class F, class A, class... Elems>
    struct ForEach<0, F, A, Elems...> {
        void operator()(A &arg, tuple<Elems...> const& t) const {
            F()(arg, get<0>(t));
        };
        void operator()(A &arg, tuple<Elems...>& t) const {
            F()(arg, get<0>(t));
        };
    };
    template <class F, class A, class... Elems>
    void for_each(A &arg, tuple<Elems...> const& t) {
        ForEach<tuple_size<tuple<Elems...>>::value - 1, F, A, Elems...>()(arg, t);
    };
    template <class F, class A, class... Elems>
    void for_each(A &arg, tuple<Elems...>& t) {
        ForEach<tuple_size<tuple<Elems...>>::value - 1, F, A, Elems...>()(arg, t);
    };

    struct hash_for_element {
        template <class V>
        void operator()(size_t &size, const V& v) const {
            size ^= hash<V>()(v);
        }
    };
}

// Input
template <class F, class S>
istream &operator>>(istream &stream, pair<F, S> &pair) {
    stream >> pair.first;
    stream >> pair.second;
    return stream;
}
template <class ...Args>
istream &operator>>(istream &stream, tuple<Args...> &tuple) {
    tuple_utils::read(stream, tuple, tuple_utils::gen_seq<sizeof...(Args)>());
    return stream;
}

template <class T>
T read() {
    T t;
    cin >> t;
    return t;
}
template <class F, class S>
pair<F, S> read() {
    pair<F, S> p;
    cin >> p;
    return p;
}
template <class T1, class T2, class T3, class ...Args>
tuple<T1, T2, T3, Args...> read() {
    tuple<T1, T2, T3, Args...> t;
    cin >> t;
    return t;
}

template <class T>
V<T> read(const int length) {
    V<T> ts(length);
    for (auto& t: ts) {
        cin >> t;
    }
    return ts;
}
template <class F, class S>
V<pair<F, S>> read(const int length) {
    V<pair<F, S>> ps(length);
    for (auto& p: ps) {
        cin >> p;
    }
    return ps;
}
template <class T1, class T2, class T3, class ...Args>
V<tuple<T1, T2, T3, Args...>> read(const int length) {
    V<tuple<T1, T2, T3, Args...>> ts(length);
    for (auto& t: ts) {
        cin >> t;
    }
    return ts;
}

// Output
namespace debug {
    template <class F, class S>
    ostream &operator<<(ostream& stream, const pair<F, S> &pair) {
        stream << "{" << pair.first << ", " << pair.second << "}";
        return stream;
    }
    template <class ...Args>
    ostream &operator<<(ostream& stream, const tuple<Args...> &tuple) {
        stream << "{";
        tuple_utils::print(stream, tuple, tuple_utils::gen_seq<sizeof...(Args)>());
        stream << "}";
        return stream;
    }

    template <class T, class Alloc>
    ostream &operator<<(ostream& stream, const vector<T, Alloc> &vector) {
        stream << "[";

        for (size_t i = 0; i < vector.size(); i++) {
            stream << vector[i];

            if (i != vector.size() - 1) {
                stream << "," << ((i % 10 == 9) ? "\n " : "\t");
            }
        }

        stream << "]";
        return stream;
    }
}

// Hash
namespace std {
    template <class F, class S>
    struct hash<pair<F, S>> {
        size_t operator ()(const pair<F, S> &p) const {
            return hash<F>()(p.first) ^ hash<S>()(p.second);
        }
    };

    template <class ...Args>
    struct hash<tuple<Args...>> {
        size_t operator ()(const tuple<Args...> &t) const {
            size_t retval = 0;

            tuple_utils::for_each<tuple_utils::hash_for_element, size_t, Args...>(retval, t);

            return retval;
        }
    };
}

// Data Structure
template <class T, class Compare = std::less<T>>
struct heap {
    heap () : m_heap(), m_cmp() {
    }
    heap (const V<T> &v) : m_heap(v), m_cmp() {
        make_heap(this->m_heap.begin(), this->m_heap.end(), this->m_cmp);
    }
    heap (const Compare &cmp) : m_heap(), m_cmp(cmp) {
    }
    heap (const V<T> &v, const Compare &cmp) : m_heap(v), m_cmp(cmp) {
        make_heap(this->m_heap.begin(), this->m_heap.end(), this->m_cmp);
    }

    const T &top() const {
        return this->m_heap.front();
    }
    T pop() {
        pop_heap(this->m_heap.begin(), this->m_heap.end(), this->m_cmp);
        auto retval = this->m_heap.back();
        this->m_heap.pop_back();
        return retval;
    }
    void push(const T &v) {
        this->m_heap.push_back(v);
        push_heap(this->m_heap.begin(), this->m_heap.end(), this->m_cmp);
    }

    auto size() const {
        return this->m_heap.size();
    }

    auto begin() const {
        return this->m_heap.cbegin();
    }
    auto cbegin() const {
        return this->m_heap.cbegin();
    }
    auto end() const {
        return this->m_heap.cend();
    }
    auto cend() const {
        return this->m_heap.cend();
    }
private:
    V<T> m_heap;
    Compare m_cmp;
};

int body(int &argc, char **argv);

// main function (DO NOT EDIT)
int main (int argc, char **argv) {
    ios_base::sync_with_stdio(false);
    return body(argc, argv);
}

i64 solve(i64 H, i64 W) {
    /*
     * Case 1
     * +------+
     * |      |
     * +------+
     * |      |
     * +------+
     * |      |
     * +------+
     */
    i64 r1 = numeric_limits<i64>::max();
    switch (H % 3) {
        case 0:
            r1 = 0;
            break;
        case 1:
            r1 = W;
            break;
        default:
            r1 = W;
            break;
    }

    /*
     * Case 2
     * +------+
     * |      |
     * +---+--+
     * |   |  |
     * +---+--+
     */
    i64 r2 = numeric_limits<i64>::max();
    {
        if (W % 2 == 0) {
            i32 n = H / 3;
            if (H % 3 == 0) {
                r2 = 0;
            } else {
                r2 = abs((W / 2) * (2 * H - 6 * n - 3));
            }
        } else {
            i32 n = (H - 1) / 2;
            REP (h, H) {
                auto w1 = abs(-(3*n+2)*h + H*W);
                auto w2 = abs(-(3*n+1)*h + H*W);
                i64 w3 = h;

                auto r = max(w1, max(w2, w3));

                r2 = min(r, r2);
            }
        }
    }

    return min(r1, r2);
}

int body(int &argc, char **argv) {
    auto H = read<i32>();
    auto W = read<i32>();

    auto r1 = solve(H, W);
    auto r2 = solve(W, H);

    cout << min(r1, r2) << endl;
    return 0;
}


Measured memory_bytes: 256