#include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<ctime>
#define fuck(x) cout<<#x<<" = "<<x<<endl;
#define ls (t<<1)
#define rs ((t<<1)+1)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 1024;
const int inf = 2.1e9;
const ll Inf = 999999999999999999;
const int mod = 1000000007;
const double eps = 1e-6;
const double pi = acos(-1);
bool vis[maxn];
int num[maxn];
int f[maxn];
struct node
{int id,sz;
}a[maxn];
vector<int>v[maxn];
int n,m;bool cmp(node a,node b){return a.sz<b.sz;
}int mx=1001;
int getf(int x,int t){if(t==mx){return -1;}if(x==f[x])return x;return getf(f[x],t+1);
}int get_num(int x,int t){if(t==mx){return -1;}num[x]++;if(x==f[x]){return x;}return get_num(f[x],t+1);
}vector<int>tt;
int main()
{scanf("%d",&n);for(int i=1;i<=n;i++){scanf("%d",&m);f[i]=i;for(int j=1;j<=m;j++){int x;scanf("%d",&x);v[i].push_back(x);a[i].sz++;}a[i].id=i;}sort(a+1,a+1+n,cmp);bool flag=true;for(int i=1;i<=n;i++){int siz = a[i].sz;int id=a[i].id;for(int j=0;j<siz;j++){vis[v[id][j]]=true;}vis[id]=true;for(int j=0;j<siz;j++){int t1=getf(v[id][j],0);if(id==v[id][j]||t1==-1||!vis[t1]){flag=false;break;}if(t1==v[id][j]){tt.push_back(t1);}}int sz=tt.size();for(int j=0;j<sz;j++){f[tt[j]]=id;}tt.clear();if(!flag){break;}memset(vis,0,sizeof(vis));}int rec=0;for(int i=1;i<=n;i++){if(f[i]==i){rec++;}get_num(i,0);}for(int i=1;i<=n;i++){if(num[i]!=v[i].size()+1){flag=false;}}if(rec!=1){flag=false;}if(flag){printf("YES\n");for(int i=1;i<=n;i++){if(f[i]!=i){printf("%d %d\n",f[i],i);}}}else {printf("NO\n");}return 0;
}