#include<iostream>
#include<cstdio>
#include<queue>
#include<cassert>
#define N 500
#define inf 1e9
using namespace std;
int read()
{
    char c=0;
    int sum=0;
    while (c<'0'||c>'9') c=getchar();
    while ('0'<=c&&c<='9') sum=sum*10+c-'0',c=getchar();
    return sum;
}
struct reads
{
    int x,y;
};
reads st[N+1][N+1];
struct node
{
    int v,data,nxt;
};
node edge[N*N+1];
int T,n,len,s,t,p[N+1][N+1],F[N+1][N+1],head[N+1],cur[N+1],depth[N+1];
bool used[N+1][N+1];
void add(int x,int y,int z)
{
    edge[++len]=(node){y,z,head[x]},head[x]=len;
    edge[++len]=(node){x,0,head[y]},head[y]=len;
    return;
}
bool bfs()
{
    int top;
    queue<int>q;
    for (int i=s;i<=t;++i) depth[i]=0;
    q.push(s),depth[s]=1;
    while (!q.empty())
    {
	top=q.front(),q.pop();
	for (int i=head[top];i>0;i=edge[i].nxt)
	    if (edge[i].data&&!depth[edge[i].v])
	    {
		depth[edge[i].v]=depth[top]+1,q.push(edge[i].v);
		if (edge[i].v==t) return 1;
	    }
    }
    return 0;
}
int dinic(int x,int flow)
{
    if (x==t) return flow;
    int k;
    for (int &i=cur[x];i>0;i=edge[i].nxt)
	if (edge[i].data&&depth[edge[i].v]==depth[x]+1)
	{
	    k=dinic(edge[i].v,min(flow,edge[i].data));
	    if (k)
	    {
		edge[i].data-=k,edge[i^1].data+=k;
		return k;
	    }
	}
    return 0;
}
int main()
{
    int flow,res;
    T=read();
    while (T--)
    {
	n=read();
	for (int i=1;i<=n;++i)
	    for (int j=1;j<=n;++j)
		p[i][j]=read(),used[i][j]=0;
	for (int i=1;i<=n;++i)
	{
	    s=0,t=(n<<1)+1,len=1,res=0;
	    for (int j=s;j<=t;++j) head[j]=0;
	    for (int j=1;j<=n;++j) add(s,j,1),add(j+n,t,1);
	    for (int j=1;j<=n;++j)
		for (int k=1;k<=n;++k)
		    if (!used[j][k])
			add(j,p[j][k]+n,1),F[j][p[j][k]]=k;
	    while (bfs())
	    {
		for (int j=s;j<=t;++j) cur[j]=head[j];
		while (flow=dinic(s,inf)) res+=flow;
	    }
	    for (int j=1;j<=n;++j)
		for (int k=head[j];k>0;k=edge[k].nxt)
		    if (edge[k].v>=n+1&&!edge[k].data)
			used[j][F[j][edge[k].v-n]]=1,st[j][i]=(reads){j,F[j][edge[k].v-n]};
	}
	printf("%d\n",(n*(n-1))>>1);
	for (int i=1;i<=n;++i)
	    for (int j=i+1;j<=n;++j)
		printf("%d %d %d %d\n",st[i][j].x,st[i][j].y,st[j][i].x,st[j][i].y);
    }
    return 0;
}