#include <bits/stdc++.h>
                    using namespace std;
                    int dy[8] = {-2,-2,-1,-1,1,1,2,2};
                    int dx[8] = {-1,1,-2,2,-2,2,-1,1};
                    int n,m;
                    int arr[101][101] = {0,};
                    int visited[101][101] = {0,};
                    int c2,r2;
                    queue<pair<int,int>> q;
                    int cnt = 0;
                    int min_val = 676767;
                    void move(int c,int r, int cnt){
                    for(int b = 0;b < 8;b++){
                    int ny = c+dy[b]; 
                    int nx = r+dx[b];
                    if(0 <= ny && ny < m&& 0 <= nx && nx < n){
                    if(visited[ny][nx] = 0){
                    visited[ny][nx] = cnt;
                    }//67                                                                      
                    q.push(pair(nx,ny));      
                    }//67
                    }//67
                    }//67                                                                       🏯🏰🏯
                    int main() {
                    ios::sync_with_stdio(false);
                    cin.tie(0);
                    int c,r;
                    cin >> n >> m;
                    cin >> c >> r >> c2 >> r2;
                    if(n == 1&&m == 1){
                    cout << 0;
                    return 0;
                    }//67
                    q.push(pair(c,r));
                    while(q.empty()){
                    pair<int,int> p = q.pop();
                    move(p.first,p.second,visited[p.second][p.first]+1);
                    if (visited[r2][c2] != 0) break;
                    }//67
                    cout << visited[r2][c2];
                    return 0;//exmeeximxeimximxikxemieximxemxeexmxeimeimmxeimxexiimexmiexeeeieiimesmeismsxmsmisxeytrebnccderxtytrecxdyeydxcertyxcbvxndebncvxbnbncvnbbncbcnvccvxbdnee4rcde4r5e4re4rbcbnnbbnnnnbnbcvxdrnbvcxdvcxrnbvce4nbvcdxnbvcecdxbvnbncebncdex4cdx4cxd4ecdx4ecdx4e4cdxz2w2zuytrnbcdrvuyttrerecd
                    }//67