#define _CRT_SECURE_NO_WARNINGS
#include <vector>
#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <queue>
#include <stack>

using namespace std;

class step {
public:
    long x, y, len;
    void print() {
        printf("%ld %ld\n", x, y);
    }
};

void stepprint(step *steps, long len) {
    if (len > -1)
    {
        stepprint(steps, steps[len].len);
        steps[len].print();
    }
}

int main() {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
    long xarr[8] = { 1,2,2,1,-1,-2,-2,-1 }, yarr[8] = { 2,1,-1,-2,-2,-1,1,2 };
    long field[21][21]{}, k = 0, var = 0, check = 0, cnt = 0, ptr = 1;
    bool cont = false;
    step steps[401];
    long n, m, x2, y2;
    scanf("%ld%ld%ld%ld%ld%ld", &n, &m, &steps[0].x, &steps[0].y, &x2, &y2);
    steps[0].len = -1;

    do {
        cont = false;
        for (int i = k; i <= var && !check; i++)
        {
            for (int j = 0; j < 8; j++)
            {
                long x = steps[i].x + xarr[j];
                long y = steps[i].y + yarr[j];
                if (field[x][y] != 0 || x < 1 || x > n || y < 1 || y > m)
                {
                    continue;
                }
                else
                {
                    field[x][y]++;
                    cont = true;
                    steps[ptr].x = x; steps[ptr].y = y; steps[ptr].len = i;
                    ptr++;
                    if (x == x2 && y == y2)
                    {
                        check = ptr - 1;
                        break;
                    }
                }
            }
        }
        cnt++;
        k = var + 1;
        var = ptr - 1;
    } while (!check && cont);

    if (check)
    {
        printf("%ld\n", cnt);
        stepprint(steps, check);
    }
    else
    {
        printf("-1");
    }

    return 0;
}