#include<bits/stdc++.h>
using namespace std;
class dsu {
public:
vector<int> par, ct;
dsu(int sz) {
ct.resize(sz, 1);
par.resize(sz);
iota(par.begin(), par.end(), 0);
}
int get_par(int nd) {
return (par[nd] == nd ? nd : get_par(par[nd]));
}
bool Merge(int a, int b) {
a = get_par(a), b = get_par(b);
if (a == b) return false;
if (ct[a] < ct[b]) swap(a, b);
ct[a] += ct[b];
par[b] = a;
return true;
}
};
int main () {
ios_base::sync_with_stdio(0);
cin.tie(0);
int type, n;
cin >> type >> n;
vector<vector<int>> adj(n, vector<int>(n));
for (int i = 0; i < n; ++i) for (int j = 0; j < n; ++j) cin >> adj[i][j];
dsu graph(n);
vector<pair<int, int>> edges;
vector<vector<int>> g(n);
auto add_edge = [&](int val) {
for (int i = 0; i < n; ++i) for (int j = 0; j < n; ++j) {
if (adj[i][j] == val && graph.Merge(i, j)) {
edges.emplace_back(i, j);
g[i].push_back(j);
g[j].push_back(i);
}
}
};
add_edge(1); add_edge(2);
dsu col(n);
for (int i = 0; i < n; ++i) {
for (auto ad : g[i]) {
function<int(int, int)> dfs = [&](int nd, int par) {
int res = -1;
if (adj[nd][ad] == adj[nd][i]) {
return nd;
}
for (auto el : g[nd]) {
if (el == par) continue;
res = max(dfs(el, nd), res);
}
return res;
};
int source = dfs(ad, i);
if (source != -1) {
col.Merge(source, i);
}
}
}
for (int i = 0; i < n; ++i) cout << col.get_par(i) + 1 << ' ';
for (auto el : edges) cout << '\n' << el.first + 1 << ' ' << el.second + 1;
}
