Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), -1}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}
	nodes[1].depth = 0

	walk(1, 0, &nodes)
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v\n", (*nodes[i]).id, (*nodes[i]).depth)
	}
}

var time int
var record [100][100]bool
var q Queue

func walk(nid int, from int, nodes *map[int]*node) {
	q.Enqueue((*nodes)[nid])
	for !q.IsEmpty() {
		n := q.Dequeue().(*node)
		for _, v := range n.nexts {
			n2 := (*nodes)[v]
			if n2.depth != -1 {
				continue
			}
			n2.depth = n.depth + 1
			q.Enqueue((*nodes)[v])
		}
	}
}

type node struct {
	id    int
	nexts []int
	depth int
}

// Queue is Queue
type Queue struct {
	val []interface{}
}

// Enqueue value
func (queue *Queue) Enqueue(val interface{}) {
	queue.val = append(queue.val, val)
}

// Dequeue value
func (queue *Queue) Dequeue() interface{} {
	res := queue.val[0]
	queue.val = queue.val[1:len(queue.val)]
	return res
}

// IsEmpty return true when queue is empty
func (queue *Queue) IsEmpty() bool {
	return len(queue.val) == 0
}

C++: #include "bits/stdc++.h"
 
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
#define int ll
#define fi first
#define se second
#define SORT(a) sort(a.begin(),a.end())
#define rep(i,n) for(int i = 0;i < (n) ; i++) 
#define REP(i,n) for(int i = 0;i < (n) ; i++) 
#define MP(a,b) make_pair(a,b)
#define pb(a) push_back(a)
#define INF LLONG_MAX/2
#define all(x) (x).begin(),(x).end()
#define debug(x) cerr<<#x<<": "<<x<<endl
#define debug_vec(v) cerr<<#v<<":";rep(i,v.size())cerr<<" "<<v[i];cerr<<endl
/*----------------------------------------------------------------*/

// int MOD = 998244353;
int MOD = 1000000007;

int n;
vector<int> G[101];
int d[101];
void bfs(){
    rep(i,n)d[i] = INF;
    d[0] = 0;
    queue<int> q;
    q.push(0);

    while(q.size()){
        int p = q.front();
        q.pop();
        for(auto x:G[p]){
            if(d[x] == INF){
                d[x] = d[p]+1;
                q.push(x);
            }
        }
    }
}


/*----------------------------------------------------------------*/
signed main(){

    cin >> n;
    rep(i,n){
        int u,k;
        cin >> u >> k;
        rep(i,k){
            int v;
            cin >> v;
            G[u-1].pb(v-1);
        }
    }
    bfs();
    rep(i,n)if(d[i] == INF)d[i] = -1;
    rep(i,n)cout << i+1 << " " << d[i] << endl;


	return 0;
}
/*----------------------------------------------------------------*/

// g++ -std=c++14 code1.cpp
// sudo pip3 install --upgrade online-judge-tools
// rm -r -f test;oj dl https://code-festival-2018-quala.contest.atcoder.jp/tasks/code_festival_2018_quala_c
// rm -r -f test;oj dl https://pakencamp-2019-day3.contest.atcoder.jp/tasks/pakencamp_2019_day3_c
// rm -r -f test;oj dl https://joi2009yo.contest.atcoder.jp/tasks/joi2009yo_d

C++: #include <sstream>
#include <string>
#include <vector>
#include <map>
#include <algorithm>
#include <iostream>
#include <utility>
#include <set>
#include <cctype>
#include <queue>
#include <stack>
#include <cstdio>
#include <cstdlib>
#include <cmath>
using namespace std;

int main(void) {
    int n;
    cin >> n;
    int ans[n][n];
    int d[n];
    for (int i = 0; i < n; i++) d[i] = -1;
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            ans[i][j] = 0;
    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int tmp;
            cin >> tmp;
            ans[u-1][tmp-1] = 1;
        }
    }
//    for (int i = 0; i < n; i++) {
//        for (int j = 0; j < n; j++) {
//            if (j == n-1) cout << ans[i][j];
//            else cout << ans[i][j] << " ";
//        }
//        cout << endl;
//    }
    d[0] = 0;
    queue<int> q;
    q.push(0);
    while (!q.empty()) {
        int now = q.front(); q.pop();
        for (int i = 0; i < n; i++) {
            if (ans[now][i] == 1 && d[i] == -1) {
                d[i] = d[now] + 1;
                q.push(i);
            }
        }
    }
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i+1, d[i]);
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace  std;

const int nIMPOS = -1;
struct StDist
{
  int m_nDist;
  int m_nMeTo;

  StDist(int nDist) : m_nDist(nDist), m_nMeTo(0)
  { }
};

void fnInput(vector<vector<int>>& rvvnAdjcy, vector<StDist>& rvoDist)
{
  int nxSiz;
  cin >> nxSiz;

  rvvnAdjcy.resize(nxSiz + 1, vector<int>(nxSiz + 1, 0));
  for (int i = 0; i < nxSiz; ++i)
  {
    int nx, nySiz;
    cin >> nx >> nySiz;
    for (int j = 0; j < nySiz; ++j)
    {
      int ny;
      cin >> ny;
      rvvnAdjcy[nx][ny] = 1;
    }
  }
  StDist oDist(nIMPOS);
  rvoDist.resize(nxSiz + 1, oDist);
}

void fnBreadthFirstSearch(const vector<vector<int>>& cnrvvnAdjcy, 
                          queue<int>& rqnBFSrch, vector<StDist>& rvoDist)
{
  while (rqnBFSrch.size())
  {
    int nx = rqnBFSrch.front(); rqnBFSrch.pop();
    if (rvoDist[nx].m_nMeTo)  continue; 

    rvoDist[nx].m_nMeTo = 1;
    for (int ny = 1; ny < cnrvvnAdjcy[nx].size(); ++ny)
      if (cnrvvnAdjcy[nx][ny])
      {
        int nDist = rvoDist[nx].m_nDist + 1;
        if (rvoDist[ny].m_nDist == nIMPOS)
          rvoDist[ny].m_nDist = nDist;
        else
          rvoDist[ny].m_nDist = min(rvoDist[ny].m_nDist, nDist);

        rqnBFSrch.push(ny);
      }
  }
}

void fnResult(const vector<StDist>& cnrvoDist)
{
  for (int i = 1; i < cnrvoDist.size(); ++i)
    cout << i <<  " " << cnrvoDist[i].m_nDist << endl;
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  vector<vector<int>> vvnAdjcy;
  queue<int>  qnBFSrch;
  vector<StDist> voDist;

  fnInput(vvnAdjcy, voDist);

  voDist[1].m_nDist = 0;
  qnBFSrch.push(1);
  fnBreadthFirstSearch(vvnAdjcy, qnBFSrch, voDist);
  fnResult(voDist);

  return 0;
}

C++: #include <iostream>
#include <queue>

int n;

int V[100][100];
int D[100];
int d = 0;

std::queue<int> Q;

void bfs(int r) {
    Q.push(r);
    D[r] = 0;
    while (Q.size()) {
        r = Q.front();
        Q.pop();
        for (int i = 0; i < n; i++) {
            if ((D[i] == 0) && (V[r][i] == 1)) {
                Q.push(i);
                D[i] = D[r] + 1;
            }
        }
    }
}


int main() {
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        int id, e_num;
        std::cin >> id >> e_num;
        for (int j = 0; j < e_num; j++) {
            int t;
            std::cin >> t;
            V[id - 1][t - 1] = 1;
        }
    }

    bfs(0);
    for (int i = 0; i < n; i++) {
        std::cout << i + 1 << " " << D[i] << std::endl;
    }
}