import std.stdio, std.string, std.conv;
import std.range, std.algorithm, std.array, std.typecons, std.container;
import std.math, std.numeric, core.bitop;

enum inf3 = 1_001_001_001;
enum inf6 = 1_001_001_001_001_001_001L;
enum mod = 1_000_000_007L;


void main() {
    int h, w;
    scan(h, w);

    long ans = min(solve(h, w), solve(w, h));
    writeln(ans);
}

long solve(int h, int w) {
    long ans = inf6;

    foreach (x ; 0 .. w + 1) {
        long b = 1L * h * x;
        long a = 1L * (h / 2) * (w - x);
        long c = 1L * ((h + 1) / 2) * (w - x);
        auto m = max(abs(a - b), abs(a - c), abs(b - c));
        ans = min(ans, m);

        a = 1L * h * ((w - x) / 2);
        c = 1L * h * ((w - x + 1) / 2);
        m = max(abs(a - b), abs(a - c), abs(b - c));
        ans = min(ans, m);
    }

    return ans;
}








void scan(T...)(ref T args) {
    import std.stdio : readln;
    import std.algorithm : splitter;
    import std.conv : to;
    import std.range.primitives;

    auto line = readln().splitter();
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}

void fillAll(R, T)(ref R arr, T value) {
    static if (is(typeof(arr[] = value))) {
        arr[] = value;
    }
    else {
        foreach (ref e; arr) {
            fillAll(e, value);
        }
    }
}
