#include <iostream>
#include <math.h>
#include <cmath>
#include <algorithm>
#include <iomanip>
#include <queue>
#include <stack>
#include <climits>

using namespace std;

struct horse {
    long x, y, l;
};

void print(horse* onewhitehorse, long v) {
    if (v > -1)
    {
        print(onewhitehorse, onewhitehorse[v].l);
        cout << onewhitehorse[v].x << " " << onewhitehorse[v].y<<endl;
    }
}

int main() {
   // freopen("input.txt", "r", stdin);
   // freopen("output.txt", "w", stdout);
    int x[8] = { 1,2,2,1,-1,-2,-2,-1 };
    int y[8] = { 2,1,-1,-2,-2,-1,1,2 };
    long area[50][50]{};
    bool end = false;
    int s = 1, klv = 0, v = 0, u = 0, k = 0;
    horse one[1000];
    long n, m, x2, y2;
    cin >> n >> m >> one[0].x >> one[0].y >> x2 >> y2;
    one[0].l = -1;

    do {
        end = false;
        for (int i = k; v == false && i <= u; i++) {
            for (int j = 0; j < 8; j++) {
                long y1 = one[i].y + y[j];
                long x1 = one[i].x + x[j];
                if (x1 < 1 || y1 < 1 || area[x1][y1] != 0 || x1 > n || y1 > m) continue;
                else{
                    end = true;
                    area[x1][y1]++;
                    one[s].l = i;
                    one[s].x = x1; one[s].y = y1;
                    s++;
                    if (x1 == x2 && y1 == y2){
                        v = s - 1; break;
                    }
                }
            }
        }
        klv++;
        k = u + 1;
        u = s - 1;
    } while (v == false && end == true);

    if (v == true) {
        cout << klv << endl;
        print(one, v);
    }
    else cout << "-1";
}