#define _CRT_SECURE_NO_WARNINGS
#include <stdlib.h>
#include <stdio.h>
#include <iostream>
#include <math.h>
#include <map>
#include <set>
#include <stack>
#include <vector>
#include <time.h>
#include <random>
#include <algorithm>
#include <string>
#include <string.h>
#include <queue>
#include <deque>
#include <functional>
#include <cctype>
#include <list>
#define rt return
#define rt0 return 0
#define rt1 return 1
#define mp make_pair
#define cen cout << "\n"
#define endl "\n"
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double db;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const ll inf = 1000000009;
const int sz = 310;
char ar[sz][sz][sz];
int n, w, h, xs = -1, ys;

char dfs(int t, int x, int y){
    if (x < 0 || x >= w || y < 0 || y >= h || ar[t][x][y] == 2)
        rt 2;
    if (ar[t][x][y])
        rt ar[t][x][y];
    if (t == n - 1)
        rt ar[t][x][y] = 1;
    if (dfs(t + 1, x - 1, y) == 1)
        rt ar[t][x][y] = 1;
    if (dfs(t + 1, x + 1, y) == 1)
        rt ar[t][x][y] = 1;
    if (dfs(t + 1, x, y - 1) == 1)
        rt ar[t][x][y] = 1;
    if (dfs(t + 1, x, y + 1) == 1)
        rt ar[t][x][y] = 1;
    rt ar[t][x][y] = 2;
}
void df(int t, int x, int y){
    cout << x + 1 << " " << y + 1 << endl;
    if (ar[t + 1][x - 1][y] == 1)
        df(t + 1, x - 1, y);
    else if (ar[t + 1][x + 1][y] == 1)
        df(t + 1, x + 1, y);
    else if (ar[t + 1][x][y - 1] == 1)
        df(t + 1, x , y- 1);
    else if(ar[t + 1][x][y + 1] == 1)
        df(t + 1, x, y + 1);

}
int main(){
    freopen("broadcast.in", "r", stdin);
    freopen("broadcast.out", "w", stdout);
    cin >> w >> h >> n;
    for (int i = 0; i < n; ++i){
        int x1, y1, x2, y2;
        cin >> x1 >> y1 >> x2 >> y2;
        --x1; --x2; --y1; --y2;
        for (int j = x1; j <= x2; ++j){
            for (int k = y1; k <= y2; ++k){
                ar[i][j][k] = 2;
            }
        }
    }
    for (int j = 0; j < w; ++j){
        for (int k = 0; k < h; ++k){
            if (dfs(0, j, k) == 1){
                xs = j; ys = k;
                break;
            }
        }
        if (xs != -1)
            break;
    }
    if (xs == -1){
        cout << "Impossible";
        rt0;
    }
    df(0, xs, ys);

    return 0;
}