https://ac.nowcoder.com/acm/contest/321/B
题解：结构体排序

/*
*@Author:   STZG
*@Language: C++
*/
#include <bits/stdc++.h>
#include<iostream>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<string>
#include<vector>
#include<bitset>
#include<queue>
#include<deque>
#include<stack>
#include<cmath>
#include<list>
#include<map>
#include<set>
//#define DEBUG
#define RI register int
using namespace std;
typedef long long ll;
//typedef __int128 lll;
const int N=10000+100;
const int MOD=1e9+7;
const double PI = acos(-1.0);
const double EXP = 1E-8;
const int INF = 0x3f3f3f3f;
int t,n,m,k,q;
struct node{
    int id,x;
}e[N];
bool cmp(node a,node b){
    if(a.x==b.x)
        return a.id<b.id;
    return a.x<b.x;
}
int main()
{
#ifdef DEBUG
	freopen("input.in", "r", stdin);
	//freopen("output.out", "w", stdout);
#endif
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;++i) {

            e[i].id=i;
    }
    while(n--){
        scanf("%d",&t);
        for(int i=1;i<=t;++i) {
            scanf("%d",&k);
            e[k].x++;
        }
    }
    sort(e+1,e+m+1,cmp);
    for(int i=1;i<=m;++i) {
            cout << e[i].id<<" "<<e[i].x<<endl;
    }
    //cout << "Hello world!" << endl;
    return 0;
}