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#include <bits/stdc++.h>

namespace IO {

inline char read() {
    static const int IN_LEN = 1000000;
    static char buf[IN_LEN], *s, *t;
    s == t ? t = (s = buf) + fread(buf, 1, IN_LEN, stdin) : 0;
    return s == t ? -1: *s++;
}

template<typename T>
inline void read(T &x) {
    static char c;
    static bool iosig;
    for (c = read(), iosig = false; !isdigit(c); c = read()) {
        if (c == -1) return;
        c == '-' ? iosig = true : 0;
    }
    for (x = 0; isdigit(c); c = read())
        x = (x + (x << 2) << 1) + (c ^ '0');
    iosig ? x = -x : 0;
}

const int OUT_LEN = 1000000;

char obuf[OUT_LEN], *oh = obuf;

inline void print(char c) {
    oh == obuf + OUT_LEN ? (fwrite(obuf, 1, OUT_LEN, stdout), oh = obuf) : 0;
    *oh++ = c;
}

template<typename T>
inline void print(T x) {
    static int buf[30], cnt;
    if (x == 0) {
        print('0');
    } else {
        x < 0 ? (print('-'), x = -x) : 0;
        for (cnt = 0; x; x /= 10) buf[++cnt] = x % 10 | 48;
        while (cnt) print((char)buf[cnt--]);
    }
}

inline void print(const char *s) {
    for (; *s; s++) print(*s);
}

inline void flush() {
    fwrite(obuf, 1, oh - obuf, stdout);
}
}

namespace Task {

#define long long long

long ans = LLONG_MAX;
long min = LLONG_MAX, max = LLONG_MIN;

inline void update(long p, long w, long h) {
    if (p == 0 || p >= w) return;
    min = p * h, max = p * h;
    register int l = (w - p) / 2;
    if (l > 0 && w - p - l > 0) 
        ans = std::min(ans, std::max(max, std::max(l * h, (w - p - l) * h)) - 
                        std::min(min, std::min(l * h, (w - p - l) * h)));
    l = (w - p) / 2 - 1;
    if (l > 0 && w - p - l > 0)
        ans = std::min(ans, std::max(max, std::max(l * h, (w - p - l) * h)) - 
                        std::min(min, std::min(l * h, (w - p - l) * h)));
    l = (w - p) / 2 + 1;
    if (l <= w && w - p - l > 0)
        ans = std::min(ans, std::max(max, std::max(l * h, (w - p - l) * h)) - 
                        std::min(min, std::min(l * h, (w - p - l) * h)));
    w -= p, l = h / 2;
    if (l > 0 && h - l > 0) 
        ans = std::min(ans, std::max(max, std::max(l * w, (h - l) * w)) - 
                        std::min(min, std::min(l * w, (h - l) * w)));
    l = h / 2 - 1;
    if (l > 0 && h - l > 0)
        ans = std::min(ans, std::max(max, std::max(l * w, (h - l) * w)) - 
                        std::min(min, std::min(l * w, (h - l) * w)));
    l = h / 2 + 1;
    if (l <= w && h - l > 0)
        ans = std::min(ans, std::max(max, std::max(l * w, (h - l) * w)) - 
                        std::min(min, std::min(l * w, (h - l) * w)));
}

inline void solve() {
    using namespace IO;
    register long h, w;
    read(h), read(w);
    if (h % 3 == 0 || w % 3 == 0) {
        print("0\n");
    } else if (w == 2 || h == 2) {
        print("1\n");
    } else {
        register long area = h * w / 3;
        register long ph = h / 3, pw = w / 3;
        update(pw, w, h), update(pw - 1, w, h), update(pw + 1, w, h), 
        update(pw + 2, w, h), update(pw - 2, w, h);
        update(ph, h, w), update(ph - 1, h, w), update(ph + 1, h, w),
        update(ph - 2, h, w), update(ph + 2, h, w);
        print(ans), print('\n');
    }
}
}
int main() {
#ifdef DBG
    freopen("in.in", "r", stdin);
#endif
    Task::solve();
    IO::flush();
    return 0;
}


Measured memory_bytes: 256