#include <iostream>
#include <fstream>
#include <iomanip>
#include <vector>
#include <set>
#include <map>
#include <cstring>
#include <string>
#include <cmath>
#include <cassert>
#include <ctime>
#include <algorithm>
#include <sstream>
#include <list>
#include <queue>
#include <deque>
#include <stack>
#include <cstdlib>
#include <cstdio>
#include <iterator>
#include <functional>
#include <unordered_set>
#include <unordered_map>
#include <stdio.h>
#include <bitset>
#include <cstdint>
#include <cassert>
#include <functional>
#include <complex>
#include <random>
using namespace std;
#define ll long long
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ld long double
const ll maxn = 3e3 + 10, maxm = 3e5 + 1;
const ll mod = 1e9 + 7, cmod = 998244353, inf = 1e9, blcok = 400, p2 = 31;
const ld eps = 1e-9;
int s;
int n, c;
int p[maxn], sz[maxn], used[maxn], color[maxn];
int a[maxn][maxn];
vector<int> g[maxn];
int get(int v){
if (v == p[v])
return v;
return p[v] = get(p[v]);
}
void unite(int a, int b){
int u = a, v = b;
a = get(a), b = get(b);
if (a == b)
return;
g[u].pb(v);
g[v].pb(u);
if (sz[a] > sz[b])
swap(a, b);
sz[b] += sz[a];
p[a] = b;
}
int dfs2(int v, int p, int root, int cur = 1){
if (p){
used[color[v]] += 1;
if (used[color[v]] == 1){
if (a[root][v] == cur){
return color[v];
}
++cur;
}
}
for (auto to : g[v]){
if (color[to] > 0 && to != p){
int x = dfs2(to, v, root, cur);
if (x > 0)
return x;
}
}
used[color[v]] -= 1;
return 0;
}
void dfs(int v = 1, int p = 0){
if (p){
color[v] = dfs2(v, 0, v);
if (color[v] == 0){
color[v] = ++c;
}
for (int j = 1; j <= n; ++j){
used[j] = 0;
}
}
for (auto to : g[v]){
if (to != p){
dfs(to, v);
}
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cin >> s;
cin >> n;
for (int i = 1; i <= n; ++i){
p[i] = i, sz[i] = 1;
}
for (int i = 1; i <= n; ++i){
for (int j = 1; j <= n; ++j){
cin >> a[i][j];
if (a[i][j] == 1){
unite(i, j);
}
}
}
vector<int> roots;
for (int i = 1; i <= n; ++i){
int x = get(i);
if (used[x] == 0){
roots.pb(x);
}
}
for (int i = 0; i < (int)roots.size(); ++i){
int x = roots[i];
for (int j = i + 1; j < (int)roots.size(); ++j){
int y = roots[j];
if (a[x][y] == 2){
unite(x, y);
}
}
}
color[1] = 1;
c = 1;
dfs();
for (int i = 1; i <= n; ++i){
cout << color[i] << " ";
}
cout << '\n';
for (int i = 1; i <= n; ++i){
for (auto it : g[i]){
if (i < it){
cout << i << " " << it << '\n';
}
}
}
}
/*
*/
