#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ld long double
#define all(a) (a).begin(), (a).end()
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#define fr first
#define sc second
#define int long long
#define rc(s) return cout<<s,0
#define rcc(s) cout<<s,exit(0)

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

const int nmax = 2500;

int n, a[505][505], par[nmax], cost[nmax], curr, maxi;
vector<pair<int,int>>parinti[nmax];

int32_t main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
    cin >> n;
    curr = n;
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            cin >> a[i][j];
            maxi = max(maxi, a[i][j]);
        }
    }
    for(int i=1;i<=n;i++) cost[i] = a[i][i];
    for(int i=1;i<=n;i++){
        for(int j=1;j<=n;j++){
            if(i != j){
                parinti[i].push_back({a[i][j], 0});
            }
        }
    }
    for(int i=1;i<=n;i++){
        sort(all(parinti[i]));
        parinti[i].resize(unique(all(parinti[i])) - parinti[i].begin());
    }
    for(int i=1;i<=n;i++){
        reverse(all(parinti[i]));
    }
    for(int i=0;i<(int)parinti[1].size();i++){
        ++curr;
        cost[curr] = parinti[1][i].fr;
        parinti[1][i].sc = curr;
        if(i > 0){
            par[curr] = parinti[1][i-1].sc;
        }
    }
    par[1] = parinti[1].back().sc;
    for(int i=2;i<=n;i++){
        int mini = 1e18;
        for(int j=i-1;j>=1;j--){
            mini = min(mini, a[i][j]);
        }
        pair<int,int>it1;
        for(int j=i-1;j>=1;j--){
            if(a[i][j] == mini){
                for(auto it : parinti[j]){
                    if(it.fr == mini) it1 = it;
                }
            }
        }
        for(int j=0;j<(int)parinti[i].size();j++){
            if(parinti[i][j].fr < it1.fr){
                curr++;
                par[curr] = it1.sc;
                cost[curr] = parinti[i][j].fr;
                parinti[i][j].sc = curr;
                it1 = parinti[i][j];
            }
        }
        par[i] = it1.sc;
    }
    cout << curr << '\n';
    for(int i=1;i<=curr;i++) cout << cost[i] << ' ';
    cout << '\n';
    cout << n + 1 << '\n';
    for(int i=1;i<=curr;i++){
        if(i != n + 1){
            cout << i << ' ' << par[i] << '\n';
        }
    }
}


