#ifndef _GLIBCXX_NO_ASSERT
#include <cassert>
#endif
#include <cctype>
#include <cerrno>
#include <cfloat>
#include <ciso646>
#include <climits>
#include <clocale>
#include <cmath>
#include <csetjmp>
#include <csignal>
#include <cstdarg>
#include <cstddef>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>

#if __cplusplus >= 201103L
#include <ccomplex>
#include <cfenv>
#include <cinttypes>
#include <cstdbool>
#include <cstdint>
#include <ctgmath>
#include <cwchar>
#include <cwctype>
#endif

// C++
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <exception>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iosfwd>
#include <iostream>
#include <istream>
#include <iterator>
#include <limits>
#include <list>
#include <locale>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <ostream>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <stdexcept>
#include <streambuf>
#include <string>
#include <typeinfo>
#include <utility>
#include <valarray>
#include <vector>

#if __cplusplus >= 201103L
#include <array>
#include <atomic>
#include <chrono>
#include <condition_variable>
#include <forward_list>
#include <future>
#include <initializer_list>
#include <mutex>
#include <random>
#include <ratio>
#include <regex>
#include <scoped_allocator>
#include <system_error>
#include <thread>
#include <tuple>
#include <typeindex>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#endif
using namespace std;

typedef long long ll;
//typedef pair<int,int> Pint;
typedef pair<ll, ll> P;
//typedef pair<int, pair<int, int>> P;
//typedef tuple<int,int,int> T;
typedef vector<ll> vec;
typedef vector<vec> mat;
#define rep(i, n) for(ll i = 0; i < n; i++)
#define revrep(i, n) for(ll i = n-1; i >= 0; i--)
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll INFL = 1000000000000000010;//10^18 = 2^60
int INF = 1000000000;//10^9
ll MOD  = 1000000007;
//vector<int> dy = {0,0,1,-1};
//vector<int> dx = {1,-1,0,0};


int main(){
  ll H, W; cin >> H >> W;
  if(H * W % 3 == 0){
    cout << 0 << endl;
    return 0;
  }
  if(H == 1 || W == 1){
    cout << 1 << endl;
    return 0;
  }
  ll ans = H * W;
  for(int i  = 1; i <= H - 1; i++){
    ll left = i * W;
    //残りの長方形
    //(H-i) * W;
    ll right1, right2;
    if((H-i) % 2 == 0 || W % 2 == 0){
      right1 = (H-i) * W / 2;
      right2 = (H-i) * W / 2;
    }else{
      right1 = min(H-i, W) * (max(H-i, W) / 2);
      right2 = min(H-i, W) * (max(H-i, W) / 2 + 1);
    }
    if(left > right1) swap(left, right1);
    if(left > right2) swap(left, right2);
    if(right1 > right2) swap(right1, right2);
    ll sa = right2 - left;
    ans = min(ans, sa);
  }
  for(int i  = 1; i <= W - 1; i++){
    ll left = i * H;
    //残りの長方形
    //(W-i) * H;
    ll right1, right2;
    if((W-i) % 2 == 0 || H % 2 == 0){
      right1 = (W-i) * H / 2;
      right2 = (W-i) * H / 2;
    }else{
      right1 = min(W-i, H) * (max(W-i, H) / 2);
      right2 = min(W-i, H) * (max(W-i, H) / 2 + 1);
    }
    if(left > right1) swap(left, right1);
    if(left > right2) swap(left, right2);
    if(right1 > right2) swap(right1, right2);
    ll sa = right2 - left;
    ans = min(ans, sa);
  }
  cout << ans << endl;
}


Measured memory_bytes: 256