//####################################################################
//#####In the Name Of Allah,the Most Gracious,the Most Merciful.######
//####################################################################
//############Created by Sazid Rahman Simanto on 3/20/17.#############
//#####Copyright 2017 Sazid Rahman Simanto. All rights reserved.######
//####################################################################

#include <iostream>
#include <string>
#include <sstream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <stack>
#include <queue>
#include <unordered_map>
#include <deque>
#include <vector>
#include <utility>
#include <bitset>
#include <list>
#include <algorithm>
#include <complex>

using namespace std;
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//using namespace __gnu_pbds;

#define MSET(a,x) memset(a,x,sizeof a)
#define FOR(i,x,y) for(int i=(x);i<=(y);i++)
#define FORR(i,x,y) for(int i=(x);i<(y);i++)
#define ROF(i,x,y) for(int i=(y);i>=(x);i--)
#define SQ(x) ((x)*(x))
#define ALL(x) (x).begin(),(x).end()
#define SZ(x) ((int)(x).size())
#define ff first
#define ss second
#define pb push_back
#define inf             1061109567
#define maxn            100010
#define esp             1e-8
#define mod             1000000007
#define ll              long long
#define ull             unsigned long long
#define pii             pair<int,int>
#define pll             pair<ll,ll>
#define read()          freopen("input.txt", "r", stdin)
#define write()         freopen("output.txt", "w", stdout)

//typedef tree <int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pb_ds;

typedef pair<long long , ll> ii;
typedef complex<double> base;
const double PI = acos(- 1);


template <class T> inline T bigmod(T a, T b, T M) {
        ll ret = 1;
        for(; b > 0; b >>= 1) {
                if(b & 1) ret = (ret * a) % M;
                a = (a * a) % M;
        }
        return (T)ret;
}
template <class T> inline T gcd ( T a, T b ) {

        while (b) {
                a = a % b;
                swap ( a, b );
        }
        return a;
}


template <class T> inline T lcm(T a, T b) { return (a / gcd(a, b)) * b; }

template <class T> inline T poww(T a, T b) {
        ll ret = 1;
        for(; b > 0; b >>= 1) {
                if(b & 1) ret = ret * a;
                a = a * a;
        }
        return (T)ret;
}

pii exEuclid(int a, int b) {
        if(b == 0) return pii(1, 0);
        else {
                pii r = exEuclid(b, a % b);
                return pii(r.ss, r.ff - r.ss * (a / b));
        }
}

int modInv(int a, int m) { pii ret = exEuclid(a, m); return ((ret.ff % m) + m ) % m; }

int Set(int N, int pos) {return N = N | (1 << pos);}
int reset(int N, int pos) {return N = N & ~ (1 << pos);}
bool check(int N, int pos) {return (bool) (N & (1 << pos));}

//####################################################################
//##################Template Ends Here################################
//####################################################################
ll row, col;

int main() {

        //read();
        //ios_base::sync_with_stdio(false); cin.tie(NULL);cout.tie(NULL);
        //write();
        cin >> row >> col;
        ll ans = 1e18, a, b, c, mx, mi;
        FOR(i, 1, row - 2){
                a = i * col;
                ll mid = (row - i) / 2;
                b = mid * col;
                c = ((row - i) - mid) * col;
                mx = max(a, max(b, c));
                mi = min(a, min(b, c));
                ans = min(ans, mx - mi);
        }

        FOR(i, 1, row - 1){
                a = i * col;
                ll mid = col / 2;
                b = mid * (row - i);
                c = (col - mid) * (row - i);
                mx = max(a, max(b, c));
                mi = min(a, min(b, c));
                ans = min(ans, mx - mi);
        }

        FOR(i, 1, col - 2){
                a = i * row;
                ll mid = (col - i) / 2;
                b = mid * row;
                c = ((col - i) - mid) * row;
                mx = max(a, max(b, c));
                mi = min(a, min(b, c));
                ans = min(ans, mx - mi);
        }

        FOR(i, 1, col - 1){
                a = i * row;
                ll mid = row / 2;
                b = mid * (col - i);
                c = (row - mid) * (col - i);
                mx = max(a, max(b, c));
                mi = min(a, min(b, c));
                ans = min(ans, mx - mi);
        }
        cout << ans << endl;
        return 0;

}


Measured memory_bytes: 256