#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> ii;
typedef pair<ll,ll> pll;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<ll> vll;
typedef vector<pll> vpll;
#define PB push_back
#define PF push_front
#define PPB pop_back
#define PPF pop_front
#define X first
#define Y second
#define MP make_pair
#define all(x) (x).begin(), (x).end()
const int mod = 1e9 + 7; //998244353;
const int inf = 1e9 + 7;
const ll INF = 1e18 + 7;
const int logo = 20;
const int MAXN = 3e3 + 7;
const int off = 1 << logo;
const int trsz = off << 1;
const int dx[] = {1, -1, 0, 0};
const int dy[] = {0, 0, -1, 1};
int mat[MAXN][MAXN], pred[MAXN], col[MAXN], bio[MAXN], nod = 1;
vi g[MAXN], pop;
struct uf{
int par[MAXN], sz[MAXN];
uf(){
for(int i=1; i<MAXN; i++) par[i] = i, sz[i] = 1;
}
int find(int x){
return par[x] == x ? x : par[x] = find(par[x]);
}
bool same(int a, int b){
return find(a) == find(b);
}
void unite(int a, int b){
if(same(a, b)) return;
g[a].PB(b);
g[b].PB(a);
a = find(a), b = find(b);
if(sz[a] < sz[b]) swap(a, b);
par[b] = a;
}
}t;
int nadi_boju(int u, int cr, int p = -1){
if(p != -1 and col[u] and !bio[col[u]]){
if(mat[cr][u] == mat[cr][p]) return col[u];
}
bio[col[u]]++;
for(auto &x : g[u]){
if(x == p) continue;
int vl = nadi_boju(x, cr, u);
if(vl) return vl;
}
bio[col[u]]--;
return 0;
}
void dfs(int u, int p = -1){
fill(bio, bio + MAXN, 0);
col[u] = nadi_boju(u, u, -1);
if(col[u] == 0) col[u] = nod++;
for(auto &x : g[u]) if(x != p) dfs(x, u);
}
void solve(){
int n;
cin >> n;
for(int i=1; i<=n; i++){
for(int j=1; j<=n; j++) cin >> mat[i][j];
}
for(int i=1; i<=n; i++){
if(pred[i]) continue;
for(int j=1; j<=n; j++) if(mat[i][j] == 1) pred[j] = i;
pop.PB(i);
}
for(auto &x : pop) for(auto &y : pop) if(mat[x][y] == 2) t.unite(x, y);
dfs(1);
for(int i=1; i<=n; i++) cout << col[pred[i]] << " ";
cout << "\n";
for(int i=1; i<=n; i++){
for(auto &x : g[i]) if(i < x) cout << i << " " << x << "\n";
if(pred[i] != i) cout << pred[i] << " " << i << "\n";
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int _;
cin >> _;
solve();
return 0;
}
