/* -*- coding: utf-8 -*-
 *
 * 2928.cc:  No.2928 Gridpath - yukicoder
 */

#include<cstdio>
#include<vector>
#include<algorithm>

using namespace std;

/* constant */

const int MAX_H = 6;
const int MAX_W = 6;
const int MAX_N = MAX_H * MAX_W;

/* typedef */

using vi = vector<int>;

/* global variables */

vi nbrs[MAX_N];
int ps[MAX_N], cis[MAX_N], cs[MAX_N];
bool used[MAX_N];

/* subroutines */

/* main */

int main() {
  int h, w, sy, sx, gy, gx;
  scanf("%d%d%d%d%d%d", &h, &w, &sy, &sx, &gy, &gx);
  sy--, sx--, gy--, gx--;
  int hw = h * w, st = sy * w + sx, gl = gy * w + gx;

  for (int y = 0, u = 0; y < h; y++)
    for (int x = 0; x < w; x++, u++) {
      if (y + 1 < h)
	nbrs[u].push_back(u + w), nbrs[u + w].push_back(u);
      if (x + 1 < w)
	nbrs[u].push_back(u + 1), nbrs[u + 1].push_back(u);
    }

  ps[st] = -1;
  used[st] = true;
  for (auto v: nbrs[st]) cs[v]++;
  
  int cnt = 0;
  for (int u = st; u >= 0;) {
    auto &nbru = nbrs[u];
    int up = ps[u];

    if (u != gl && cis[u] < nbru.size()) {
      int v = nbru[cis[u]++];
      if (! used[v] && cs[v] <= 1) {
	ps[v] = u;
	used[v] = true;
	for (auto w: nbrs[v]) cs[w]++;
	u = v;
      }
    }
    else {
      if (u == gl) cnt++;
      cis[u] = 0;
      used[u] = false;
      for (auto v: nbrs[u]) cs[v]--;
      u = up;
    }
  }

  printf("%d\n", cnt);
  
  return 0;
}