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<iostream>
#include<queue>

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21); // ?????????????????????(2^21)

int n,M[N][N];
int d[N]; // ?????¢??§?¨??????¶???(color)???????????????

void bfs(int s){
	queue<int> q; // ?¨??????????????????????queue????????¨
	q.push(s);
	for(int i=0;i<n;i++) d[i] = INFTY; // ???????????????????????§??°?????\?????????
	d[s] = 0;
	int u;
	while(!q.empty()){
		u = q.front(); q.pop(); // ?????\???????????????u???????????????
		for(int v=0;v<n;v++){
			if(M[u][v] == 0) continue; // ??????u????????????v??????????????????????????°??????
			if(d[v] != INFTY) continue; // ??????v????????§????¨???????????????¨???????????°??????
			d[v] = d[u] + 1; // ??????v????????????u?????°?????????+1?????°??????????????\?????????
			q.push(v); // ?????\????????????v?????\??????
		}
	}
	for(int i=0;i<n;i++){
		cout << i+1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl; // ??????i?????°????????????INFTY??????-1???????????\???????????°????????????????????????
	}
}

int main(){
	int u, k, v;

	cin >> n;
	for(int i=0;i<n;i++){
		 for(int j=0;j<n;j++) M[i][j] = 0;
	}

	for(int i=0;i<n;i++){
		cin >> u >> k;
		u--;
		for(int j=0;j<k;j++){
			cin >> v;
			v--;
			M[u][v] = 1;
		}

C++: #include <iostream>
#include <queue>
using namespace std;
static const int N = 100;
static const int NAV = -1;

int M[N][N];

void bfs(int s, int n, int M[N][N], int d[]) {
    queue<int> Q;
    for (int i = 0; i < n; i++) d[i] = NAV;
    d[s] = 0;
    Q.push(s);

    int u;
    while (!Q.empty()) {
        u = Q.front();
        Q.pop();
        for (int v = 0; v < n; v++) {
            if (M[u][v] != 0 && d[v] == NAV) {
                d[v] = d[u] + 1;
                Q.push(v);
            }
        }
    }
}

int main() {
    int n, u, k, v;
    cin >> n;

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            M[i][j] = 0;
        }
    }

    for (int i = 0; i < n; i++) {
        cin >> u >> k;
        u--;
        for (int j = 0; j < k; j++) {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    int d[n];
    bfs(0, n, M, d);

    for (int i = 0; i < n; i++) {
        cout << i + 1 << " " << d[i] << endl;
    }

    return 0;
}

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

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21);

int n, M[N][N];
int d[N]; // ?????¢??§?¨??????¶???(color)???????????????

void bfs(int s) {
  queue<int> q; // ?¨?????????????????????? queue ????????¨
  q.push(s);
  for (int i = 0; i < n; i++) d[i] = INFTY;
  d[s] = 0;
  int u;
  while (!q.empty()) {
    u = q.front(); q.pop();
    for (int v = 0; v < n; v++) {
      if (M[u][v] == 0) continue;
      if (d[v] != INFTY) continue;
      d[v] = d[u] + 1;
      q.push(v);
    }
  }
  for (int i = 0; i < n; i++) {
    cout << i + 1 << ' ' << ( (d[i] == INFTY) ? (-1) : d[i]) << endl;
  }
}

int main() {
  int u, k, v, i, j;

  cin >> n;
  for (i = 0; i < n; i++) {
    for (j = 0; j < n; j++) M[i][j] = 0;
  }

  for (i = 0; i < n; i++) {
    cin >> u >> k;
    u--;
    for (j = 0; j < k; j++) {
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  bfs(0);

  return 0;
}

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

queue<int>Q;
int n, M[101][101], s[101];

void bfs()
{
	Q.push(1);
	s[1] = 0;

	int id = 1;

	while (true)
	{
		for (int pid = 1; pid <= n; pid++)
		{
			if (M[id][pid] == 1 && s[pid] == -1)
			{
				Q.push(pid);
				s[pid] = s[id] + 1;
			}
		}

		Q.pop();

		if (!Q.empty())
			id = Q.front();
		else
			break;
	}
}

int main()
{
	int id, pid, k;
	memset(M, 0, sizeof(M));
	memset(s, -1, sizeof(s));

	cin >> n;

	for (int i = 1; i <= n; i++)
	{
		cin >> id >> k;

		for (int j = 1; j <= k; j++)
		{
			cin >> pid;
			M[id][pid] = 1;
		}
	}

	bfs();

	for (int i = 1; i <= n; i++)
		cout << i << " " << s[i] << endl;

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
using ll = long long;
using P = pair<int, int>;

int main()
{
    int n;
    cin >> n;
    vector<vector<bool>> G(n, vector<bool>(n));
    rep(i, n)
    {
        int u, k;
        cin >> u >> k;
        rep(j, k)
        {
            int v;
            cin >> v;
            G[u - 1][v - 1] = true;
        }
    }
    queue<int> Q;
    Q.push(0);
    vector<bool> visited(n);
    vector<int> dis(n, -1);
    visited[0] = true;
    dis[0] = 0;
    while (!Q.empty())
    {
        int v = Q.front();
        Q.pop();
        rep(i, n)
        {
            if (G[v][i] && !visited[i])
            {
                Q.push(i);
                dis[i] = dis[v] + 1;
                visited[i] = true;
            }
        }
    }
    rep(i, n) printf("%d %d\n", i + 1, dis[i]);
    return 0;
}