#include<bits/stdc++.h>
#define L(i, j, k) for(int i = (j); i <= (k); ++i)
#define R(i, j, k) for(int i = (j); i >= (k); --i)
#define ll long long
#define sz(a) ((int) (a).size())
#define vi vector < int >
#define me(a, x) memset(a, x, sizeof(a))
#define ull unsigned long long
#define ld __float128
using namespace std;
const int N = 57;
int n;
int a[N][N];
ll sx[N], sy[N];
int mat[N], p[N];
bool vis[N];
bool dfs(int x) {
	L(i, 1, n) if(a[x][i]) {
		if(vis[i]) continue;
		vis[i] = true;
		if(!mat[i] || dfs(mat[i])) return mat[i] = x, p[x] = i, true;
	}
	return false;
}
vector < vi > vc;
void Main() {
	cin >> n;
	me(sx, 0), me(sy, 0);
	L(i, 1, n) {
		L(j, 1, n) {
			cin >> a[i][j];
			sx[i] += a[i][j];
			sy[j] += a[i][j];
		}
	} 
	L(i, 1, n) L(j, 1, n) if(a[i][j] < 0) {
		cout << -1 << '\n';
		return ;
	} 
	L(i, 1, n) if(sx[i] != sx[1] || sy[i] != sy[1]) {
		cout << -1 << '\n';
		return ;
	}
	vc.clear();
	bool ok = 1;
	L(i, 1, n) dfs(i); 
	while(ok) {
		int mn = 1e9;
		L(i, 1, n) mn = min(mn, a[i][p[i]]);
		vi tmp = vi{mn};
		L(i, 1, n) tmp.emplace_back(a[i][p[i]]), a[i][p[i]] -= mn;
		vc.emplace_back(tmp);
		L(i, 1, n) {
			if(!a[i][p[i]]) {
				mat[p[i]] = 0, p[i] = 0, me(vis, 0);
				if(!dfs(i)) 
					ok = 0;
			}
		}
	}
	cout << sz(vc) << '\n';
	for(auto u : vc) {
		for(auto v : u) cout << v << ' ';
		cout << '\n';
	}
}

int main () {
	ios :: sync_with_stdio(false);
	cin.tie(0); cout.tie(0); 
	int t;
	cin >> t;
	while(t--) Main();
	return 0;
}