#include<iostream>

#include<cstdio>

#include<algorithm>

#include<cmath>

#include<cstring>

#include<string>

#include<stack>

#include<queue>

#include<deque>

#include<set>

#include<vector>

#include<map>

#include<functional>

#define fst first

#define sc second

#define pb push_back

#define mem(a,b) memset(a,b,sizeof(a))

#define lson l,mid,root<<1

#define rson mid+1,r,root<<1|1

#define lc root<<1

#define rc root<<1|1

#define lowbit(x) ((x)&(-x))

using namespace std;

typedef double db;

typedef long double ldb;

typedef long long ll;

typedef unsigned long long ull;

typedef pair<int,int> PI;

typedef pair<ll,ll> PLL;

const db eps = 1e-;

const int mod = 1e9+;

const int maxn = 1e6+;

const int maxm = 1e6+;

//const int inf = 0x3f3f3f3f;

const int inf = 1e9+;

const db pi = acos(-1.0);

int n;

vector<int>v[maxn];

int f[maxn];

int ma[][];

int d[maxn];

int root;

bool sv(){

    queue<int>q;

    for(int i = ; i <= n; i++){

        if(d[i]==)q.push(i);

    }

    if(q.size()!=)return false;

    root = q.front();

    while(!q.empty()){

        int top = q.front();

        q.pop();

        for(int i = ; i < v[top].size(); i++){

            int x = v[top][i];

            d[x]--;

            if(f[x]!=-&&!ma[f[x]][top])return false;

            f[x] = top;

            if(d[x]==)q.push(x);

        }

    }

    for(int i = ; i <= n; i++){

        if(d[i]!=)return false;

    }f[root]=;

    for(int i = ; i <= n; i++){

        //if(i!=root){

            for(int j = ; j < v[i].size(); j++){

                if(!ma[f[i]][v[i][j]]){

                    //printf("--%d %d %d\n",i,f[i],v[i][j]);

                    return false;

                }

            }

        //}

    }

    return true;

}

int main() {

    scanf("%d", &n);

    for(int i = ; i <= n; i++){

        ma[][i] = ;

        f[i] = -;

        int k;

        scanf("%d", &k);

        for(int j = ; j <= k; j++){

            int x;

            scanf("%d", &x);

            v[i].pb(x);

            d[x]++;

            ma[i][x]=;

        }

    }

    mem(f,-);

    if(sv()){printf("YES\n");

    for(int i = ; i <= n; i++){

        if(i==root)continue;

        printf("%d %d\n",f[i],i);

    }}

    else printf("NO");

    return ;

}

/*

4

2 2 3

2 3 4

1 4

0

 */