#include <iostream>
#include <vector>
#include <cstring>
#include <algorithm>
#include <cassert>
#include <deque>
#include <map>
#include <queue>
#include <climits>
#include <set>
#include <stack>
#include <cmath>
#include <array>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define ll long long
#define MAX 1000
#define MAX1 10000
#define MAX2 100000
#define inf 1000000000
#define eps 1e-12
#define MOD 1000000007

set<int> sub[MAX + 5];
vector<int> graph[MAX + 5];
int sal[MAX + 5];

int nn;

void dfs(int pos, vector<pair<int, int>> &a, int u) {
    int curr = a.back().first;
    vector<int> temp;
    while (a.back().first == curr) {
        temp.push_back(a.back().second);
        a.pop_back();
    }
    if (a.size() == 1) {
        sal[pos] = a.back().first;
        graph[u].push_back(pos);
        return;
    }
    for (auto z:graph[u]) {
        if (sub[z].count(pos)) {
            dfs(pos, a, z);
            return;
        }
    }
    ++nn;
    graph[u].push_back(nn);
    sub[nn] = sub[u];
    sal[nn] = a.back().first;
    for (auto z:temp) {
        sub[nn].erase(z);
    }
    dfs(pos, a, nn);
}


int main() {

    ios_base::sync_with_stdio(0);
    cin.tie(0);
#ifndef ONLINE_JUDGE
    freopen("in.txt", "r", stdin);
    freopen("out.txt", "w", stdout);
#endif

    int n, i, j;
    cin >> n;
    vector<pair<int, int>> a[n + 5];
    for (i = 1; i <= n; ++i) {
        for (j = 1; j <= n; ++j) {
            int x;
            cin >> x;
            a[i].emplace_back(x, j);
        }
        sort(a[i].begin(), a[i].end());
    }
    nn = n + 1;
    int root = nn;
    sal[root] = a[1].back().first;
    for (i = 1; i <= n; ++i) {
        sub[root].insert(i);
    }
    for (i = 1; i <= n; ++i) {
        dfs(i, a[i], root);
    }
    cout << nn << "\n";
    for (i = 1; i <= nn; ++i) {
        cout << sal[i] << " ";
    }
    cout << "\n";
    cout << root << "\n";
    for (i = 1; i <= nn; ++i) {
        for (auto z:graph[i]) {
            cout << z << " " << i << "\n";
        }
    }

    return 0;
}
