#include<iostream>
#include<iomanip>
#include<algorithm>
#include<string>
#include<cmath>
#include<map>
#include<queue>
#include<set>
#include<vector>
#include<cstdio>
using namespace std;
int main()
{
long long H, W;
cin >> H >> W;
long long a, b, c, Min= 1000000000000;
for (int i = 1; i < H; i++) {
a = i*W;
b = (W / 2) * (H - i);
c = H*W - a - b;
Min = min(Min, max(a, max(b, c)) - min(a, min(b, c)));
b = W*((H - i) / 2);
c = H*W - a - b;
Min = min(Min, max(a, max(b, c)) - min(a, min(b, c)));
}
for (int i = 1; i < W; i++) {
a = i*H;
b = (H / 2) * (W - i);
c = H*W - a - b;
Min = min(Min, max(a, max(b, c)) - min(a, min(b, c)));
b = H*((W - i) / 2);
c = H*W - a - b;
Min = min(Min, max(a, max(b, c)) - min(a, min(b, c)));
}
cout << Min;
}