#include<bits/stdc++.h>
#define LL int
#define SZ(x) ((LL)(x.size()))
using namespace std;
inline int read(){
  int q=0,w=1;
  char ch=getchar();
  while(ch>'9' || ch<'0'){if(ch=='-')w=-1;ch=getchar();}
  while(ch>='0'&&ch<='9'){q=q*10+(ch-'0');ch=getchar();}
  return q*w;
}
void write(LL x){
  if(x<0){putchar('-');x=(-x);}
  if(x>9)write(x/10);
  putchar('0'+x%10);
}
inline void writeln(LL x){write(x);puts("");}
inline void writecs(LL x){write(x);putchar(' ');}

void lsh(vector<LL>&vc){
  sort(vc.begin(),vc.end(),[&](LL x,LL y){return x<y;});
  vc.erase(unique(vc.begin(),vc.end()),vc.end());
  return ;
}

namespace dinic{
  const int N = 100000+95 , M = 500000+95;
  LL n,s,t;
  struct Edge{
    LL to,nxt,w;
  }e[M<<1];LL head[N],tot=1,cur[N];
  inline void add(LL u,LL v,LL w){
    e[++tot].to=v;e[tot].nxt=head[u];
    e[tot].w=w;head[u]=tot;return ;
  }
  inline void add_e(LL u,LL v,LL w){
    add(u,v,w);add(v,u,0);
  }
  inline void clear(){
    for(LL i=1;i<=n;i++)head[i]=cur[i]=0;
    n=s=t=0;tot=1;return ;
  }
  LL dep[N];
  inline bool bfs(){
    for(LL i=1;i<=n;i++){dep[i]=-1;cur[i]=head[i];}
    queue<LL>q;q.push(s);dep[s]=0;
    while(!q.empty()){
      LL x=q.front();q.pop();
      for(LL i=head[x];i;i=e[i].nxt){
	if(dep[e[i].to]==-1&&e[i].w){
	  dep[e[i].to]=dep[x]+1;
	  q.push(e[i].to);
	}
      }
    }
    return (dep[t]!=-1);
  }
  inline LL dfs(LL x,LL flow){
    if(x==t)return flow;
    LL lastflow=flow;
    for(LL i=cur[x];i&&flow;i=e[cur[x]].nxt){
      cur[x]=i;
      if(dep[e[i].to]==dep[x]+1&&e[i].w){
	LL d=dfs(e[i].to,min(flow,e[i].w));
	if(d){e[i].w-=d;e[i^1].w+=d;flow-=d;}
      }
    }
    if(lastflow==flow)dep[x]=-1;
    return lastflow-flow;
  }
  inline LL solve(){
    LL maxflow=0;
    while(bfs())maxflow+=dfs(s,(LL)(1e18));
    return maxflow;
  }
}

namespace TP{
  const long long N = 200+95;
  LL lim;vector<LL>E[N];LL matchL[N],matchR[N];
  void clear(){
    for(LL i=1;i<=lim;i++){E[i].clear();matchL[i]=matchR[i]=0;}
    return ;
  }
  void add_e(LL x,LL y){E[x].push_back(y);return ;}
  bool vis[N];
  bool dfs(LL x){
    if(vis[x])return 0;
    vis[x]=1;
    for(auto y:E[x]){
      if(!matchR[y]){matchL[x]=y;matchR[y]=x;return 1;}
      if(dfs(matchR[y])){matchL[x]=y;matchR[y]=x;return 1;}
    }
    return 0;
  }
  void solve(LL CNT=-1){
    LL cnt=0;
    for(LL t=1;t<=lim;t++){
      for(LL x=1;x<=lim;x++)vis[x]=0;
      cnt+=dfs(t);
    }
    if(CNT!=-1)assert(CNT==cnt);
    return ;
  }
}

#define x1 x_tmp_1
#define y1 y_tmp_1

struct pt{LL x,y;};
const int N = 200+5;
int T,n;vector<pt>a[N][N];bool b[N][N];vector<vector<LL>>ans;LL __c[N][N];
void make(LL x0,LL y0,LL x1,LL y1){
  //  cout<<" x0 = "<<x0<<" y0 = "<<y0<<" x1 = "<<x1<<" y1 = "<<y1<<endl;
  if(x0==x1&&y0==y1){
    assert(SZ(a[x0][y0])&&!b[x0][y0]);
    a[x0][y0].pop_back();
    b[x0][y0]=1;return ;
  }
  //  cout<<" SZ(a[x0][y0]) = "<<SZ(a[x0][y0])<<endl;
  //  cout<<" SZ(a[x1][y1]) = "<<SZ(a[x1][y1])<<endl;
  //  cout<<" b[x0][y1] = "<<b[x0][y1]<<" b[x1][y0] = "<<b[x1][y0]<<endl;
  assert(SZ(a[x0][y0])&&SZ(a[x1][y1])&&!b[x0][y1]&&!b[x1][y0]);
  pt X=a[x0][y0].back();a[x0][y0].pop_back();
  pt Y=a[x1][y1].back();a[x1][y1].pop_back();
  b[x0][y1]=b[x1][y0]=1;
  ans.push_back({X.x,X.y,Y.x,Y.y});
  return ;
}

#define PLL pair<LL,LL>
#define mp(a,b) make_pair(a,b)
#define fir first
#define sec second

#define random(a,b) (rand()%(b-a+1)+a)

namespace sub{
  LL __cnt[N];
  bool check(){
    ans.clear();
    for(LL i=1;i<=n;i++)
      for(LL j=1;j<=n;j++){a[i][j].clear();b[i][j]=0;}
      
    for(LL i=1;i<=n;i++)
      for(LL j=1;j<=n;j++){a[i][__c[i][j]].push_back((pt){i,j});}

    for(LL i=1;i<=n;i++){
      LL mx=0;
      for(LL j=1;j<=n;j++)mx=max(mx,SZ(a[i][j]));
      for(LL j=1;j<=n;j++){
	if(SZ(a[i][j])==mx){mx=-1;continue;}
	if(SZ(a[i][j])>1)return false;
      }
    }
    return true;
  }
  void solve(){
    TP::lim=n;
    {
      vector<LL>ord(n+2);vector<LL>vis(n+2);for(LL i=1;i<=n;i++)vis[i]=0;
      for(LL v=1;v<=n;v++)
	for(LL i=1;i<=n;i++)
	  if(!vis[i]&&SZ(a[i][v])>=(n-1)){ord[v]=i;vis[i]=1;break;}
    
      vector<pt>tmp[n+2][n+2];
      for(LL i=1;i<=n;i++)
	for(LL j=1;j<=n;j++)tmp[i][j]=a[i][j];
      for(LL i=1;i<=n;i++)
	for(LL j=1;j<=n;j++)a[i][j]=tmp[ord[i]][j];
    }

    for(LL t=1;t<=n;t++){
      vector<LL>visL(n+2),visR(n+2);
      for(LL i=t+1;i<=n;i++)
	if(SZ(a[t][i])){make(t,i,t,i);visR[i]=1;}
      for(LL i=t+1;i<=n;i++)
	if(SZ(a[i][t])){make(i,t,i,t);visL[i]=1;}
      LL cnt=0;
      for(LL i=t+1;i<=n;i++)
	if(!b[t][i])cnt++;
      TP::clear();
      for(LL i=t+1;i<=n;i++)
	for(LL j=t+1;j<=n;j++)
	  if(!b[t][i]&&!b[j][t]&&SZ(a[j][i]))TP::add_e(i,j);
      TP::solve(cnt);
      for(LL i=t+1;i<=n;i++){
	if(b[t][i])continue;
	LL j=TP::matchL[i];
	make(t,t,j,i);
      }
    }

    writeln(SZ(ans));
    for(LL t=0;t<SZ(ans);t++){
      for(LL i=0;i<SZ(ans[t]);i++)writecs(ans[t][i]);
      puts("");
    }
    for(LL t=0;t<SZ(ans);t++){
      LL x0=ans[t][0],y0=ans[t][1],x1=ans[t][2],y1=ans[t][3];
      swap(__c[x0][y0],__c[x1][y1]);
    }
    for(LL t=1;t<=n;t++){
      vector<LL>vec(n);
      for(LL i=1;i<=n;i++)vec[i-1]=__c[t][i];
      lsh(vec);assert(SZ(vec)==n);
    }
    return ;
  }
}
int main(){
  random_device seed;srand(seed());
  T=read();
  while(T--){

    /*    n=random(1,5);
    for(LL i=1;i<=n;i++)
      for(LL j=1;j<=n;j++)__c[i][j]=i;
    while(true){
      LL v=random(0,10);
      cerr<<" v = "<<v<<endl;
      if(v==0)break;
      LL x0=random(1,n),y0=random(1,n);
      LL x1=random(1,n),y1=random(1,n);
      swap(__c[x0][y0],__c[x1][y1]);
    }

    cout<<n<<endl;
    for(LL i=1;i<=n;i++){
      for(LL j=1;j<=n;j++)cout<<__c[i][j]<<" ";
      cout<<endl;
    }*/

    n=read();
    for(LL i=1;i<=n;i++)
      for(LL j=1;j<=n;j++)__c[i][j]=read();

    if(sub::check()){
      sub::solve();
      continue;
    }

    /*    while(true){
      LL v=random(0,1000);
      cerr<<" v = "<<v<<endl;
      if(v==0)break;
      LL x0=random(1,n),y0=random(1,n);
      LL x1=random(1,n),y1=random(1,n);
      swap(__c[x0][y0],__c[x1][y1]);
      }*/

    
    /*    for(LL i=1;i<=n;i++)
      for(LL j=1;j<=n;j++)__c[i][j]=i;
    for(LL i=1;i<=n;i++)
      swap(__c[i][n],__c[random(1,n)][n]);*/

    /*    for(LL i=1;i<=n;i++){
      for(LL j=1;j<=n;j++)cout<<__c[i][j]<<" ";
      cout<<endl;
    }*/

    LL fl=0;
    while(!fl){
      fl=1;
      
      ans.clear();
      for(LL i=1;i<=n;i++)
	for(LL j=1;j<=n;j++){a[i][j].clear();b[i][j]=0;}
      
      for(LL i=1;i<=n;i++)
	for(LL j=1;j<=n;j++){a[i][__c[i][j]].push_back((pt){i,j});}
      
      {
	vector<LL>ord(n+2);vector<LL>vis(n+2);for(LL i=1;i<=n;i++)vis[i]=0;
	for(LL i=1;i<=n;i++)ord[i]=i;
	for(LL i=1;i<=n;i++)
	  swap(ord[i],ord[random(1,n)]);
	
	vector<pt>tmp[n+2][n+2];
	for(LL i=1;i<=n;i++)
	  for(LL j=1;j<=n;j++)tmp[i][j]=a[i][j];
	for(LL i=1;i<=n;i++)
	  for(LL j=1;j<=n;j++)a[i][j]=tmp[ord[i]][j];
      }

      vector<LL>idxL(n+2),idxR(n+2);LL Id=0,S=0,T=0;
      vector<vector<LL>>idL(n+2),idR(n+2);
      S=++Id;T=++Id;
      for(LL i=1;i<=n;i++)idxL[i]=++Id;
      for(LL i=1;i<=n;i++)idxR[i]=++Id;
      for(LL i=1;i<=n;i++){idL[i].resize(n+2);idR[i].resize(n+2);}
    
      for(LL t=1;t<=n;t++){
	dinic::clear();dinic::n=Id;dinic::s=S;dinic::t=T;LL Idx=Id;
      
	for(LL i=1;i<=n;i++){
	  if(!SZ(a[i][t]))continue;
	  dinic::add_e(S,idxL[i],SZ(a[i][t]));
	}
	for(LL j=1;j<=n;j++){
	  if(b[j][t])continue;
	  dinic::add_e(idxR[j],T,1);
	}
	vector<vector<LL>>vec;
	for(LL i=1;i<=n;i++){
	  vec.push_back({dinic::tot+1,i,i,t});
	  dinic::add_e(idxL[i],idxR[i],1);
	}
	LL cnt=0;
	for(LL i=1;i<=n;i++)
	  if(!b[i][t])cnt++;
	cnt-=dinic::solve();
	for(LL K=(t+1);K<=n;K+=2){
	  for(LL k=K;k<=min(K+1,n);k++){
	    for(LL i=1;i<=n;i++){
	      if(!SZ(a[i][t]))continue;
	      idL[i][k]=++Idx;
	      if((!b[i][k]))dinic::add_e(idxL[i],idL[i][k],1);
	    }
	  
	    for(LL j=1;j<=n;j++){
	      if(b[j][t])continue;
	      idR[j][k]=++Idx;
	      if(SZ(a[j][k])>=1)dinic::add_e(idR[j][k],idxR[j],1);
	    }
	  
	    dinic::n=Idx;

	    for(LL i=1;i<=n;i++)
	      if(SZ(a[i][t]))
		for(LL j=1;j<=n;j++)
		  if((!b[j][t])&&(!b[i][k])&&SZ(a[j][k])>=1){
		    vec.push_back({dinic::tot+1,i,j,k});
		    dinic::add_e(idL[i][k],idR[j][k],1);
		  }
	  }
	  cnt-=dinic::solve();
	}
	if(cnt>0){fl=0;break;}
	for(LL i=0;i<SZ(vec);i++)
	  if(!dinic::e[vec[i][0]].w)
	    make(vec[i][1],t,vec[i][2],vec[i][3]);
	dinic::clear();
      }
      if(!fl)continue;

      writeln(SZ(ans));
      for(LL t=0;t<SZ(ans);t++){
	for(LL i=0;i<SZ(ans[t]);i++)writecs(ans[t][i]);
	puts("");
      }
      for(LL t=0;t<SZ(ans);t++){
	LL x0=ans[t][0],y0=ans[t][1],x1=ans[t][2],y1=ans[t][3];
	swap(__c[x0][y0],__c[x1][y1]);
      }
      for(LL t=1;t<=n;t++){
	vector<LL>vec(n);
	for(LL i=1;i<=n;i++)vec[i-1]=__c[t][i];
	lsh(vec);assert(SZ(vec)==n);
      }
      break; 
    }
  }
  return 0;
}