Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	nodes := make([]Node, n)

	for i := 0; i < n; i++ {
		nodes[i].list = make([]int, 0)
		nodes[i].d = -1
	}

	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		u--
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			v--
			nodes[u].list = append(nodes[u].list, v)
		}
	}

	queue := make([]int, n)
	queue[0] = 0
	nodes[0].d = 0
	d := 0
	i, j := 0, 1
	for i < j {
		d++
		prev := j
		for i < prev {
			for k, l := 0, len(nodes[queue[i]].list); k < l && i < n; k++ {
				if nodes[nodes[queue[i]].list[k]].d != -1 {
					continue
				}
				nodes[nodes[queue[i]].list[k]].d = d
				queue[j] = nodes[queue[i]].list[k]
				j++
			}
			i++
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i+1, nodes[i].d))
	}

	writer.Flush()
}

// Node ...
type Node struct {
	list []int
	d    int
}

C++: #include "stdafx.h"
#include <utility>
#include <iostream>
#include <algorithm>
#include <queue>

using namespace std;

int D[110]; // ?????¢????¨???¶
int v, A[100][100], u, k, w;
queue<int> Q;

void bfs(int src) {

	Q.push(src);
	D[src] = 0;

	while (!Q.empty()) {
		int cur = Q.front();
		Q.pop();
		for (int i = 0; i < v; ++i) {
			if (A[cur][i] == 1 && D[i] == 0) {
				D[i] = D[cur] + 1;
				Q.push(i);
			}
		}
	}

	for (int l = 0; l < v; ++l) {
		if (D[l] == 0 && l != 0) { D[l] = -1; }
		cout << l+1 << " " << D[l] << endl;
	}

}

int main(){
	cin >> v;
	// ???????????§??????v
	for (int i = 0; i < v; ++i) {

		cin >> u >> k;
		// ??????????????????u???k?????\?????????????????°??????

		for (int j = 0; j < k; ++j) {

			cin >> w;
			A[u - 1][w - 1] = 1;

			// ??£??\???????????§?¨??????????????????????????????????

		}
	}

	
	bfs(0);

}

C++: #include <iostream>
#include <stdio.h>
#include <queue>
#define N 101
#define INFTY (1<<21)


int n;
int M[N][N];
int d[N];

void bfs(int u) {
    std::queue<int> Q;
    Q.push(u);
    for (int i = 0; i < n; i++) d[i] = INFTY;
    d[u] = 0;
    while ( ! Q.empty() ) {
        int j = Q.front();
        Q.pop();
        for (int v = 0; v < n; v++) {
            if (M[j][v] == 0) continue;
            if (d[v] != INFTY) continue;
            d[v] = d[j] + 1;
            Q.push(v);
        }
    }
    for (int i = 0; i < n; i++) {
        printf("%d %d\n", i+1, d[i]);
    }
}

int main() {
    int u, k, v;
    scanf("%d", &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++) {
        scanf("%d %d", &u, &k);
        u--;
        if (k == 0) continue;
        for (int j = 0; j < k; j++) {
            scanf("%d", &v);
            v--;
            M[u][v] = 1;
        }
    }
    
    bfs(0);
    
    return 0;
}

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

typedef struct{
  int A[1000];
  int ans;
  bool c;
}node;
node T[1000];
int Q[1000000];
int head=0;
int tail=1;
int n;

void function(int num){
  while(true){
    if(head==tail)break;
    for(int i=2;i<=n;i++){
      if(T[num].A[i]==1){
	if(T[i].ans==0){
	  T[i].ans=T[num].ans+1;
	}
	Q[tail++]=i;
      }
    }
    //    cout<<"Q "<<Q[head]<<endl;
    num=Q[head++];
    //  cout<<head<<" "<<tail<<endl;
  }

}

int main(){
  int num;
  int son;
  int z;
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>num;
    cin>>son;
    for(int j=0;j<son;j++){
      cin>>z;
      T[num].A[z]=1;
      }
  }
  Q[0]=1;
  function(1);
  T[1].ans=0;
  for(int i=2;i<=n;i++){
    if(T[i].ans==0){
      T[i].ans=-1;
    }
  }

  for(int i=1;i<=n;i++){
      cout<<i<<" "<<T[i].ans<<endl;
  }


  return 0;
}

C++: #include <stdio.h>
#include <iostream>
using namespace std;

class Adjl{
private:
	int u;
	int k;
	Adjl **next;
	int check_id;
public:
	Adjl(int u);
	~Adjl(){ if (next != NULL) delete[] next; }
	void setV(int k, Adjl *vk);
	int breadthFirstSearch(int id);
	void print(int id);
};

Adjl::Adjl(int u)
{
	this->u = u;
	k = 0;
	next = NULL;
	check_id = 0;
}

void Adjl::setV(int k, Adjl *vk)
{
	if (this->k == 0) next = new Adjl*[k];
	next[this->k] = vk;
	(this->k)++;
}

int Adjl::breadthFirstSearch(int id)
{
	if (id == u) return 0;

	for (int i = 0; i < k; i++) {
		if (id == next[i]->u) return 1;
	}
	for (int i = 0; i < k; i++) {
		int d = next[i]->breadthFirstSearch(id);
		if (d != -1) return d + 1;
	}
	return -1;
}

void Adjl::print(int id)
{
	cout << id << " " << breadthFirstSearch(id) << endl;
}

int main(void)
{
	int n;
	cin >> n;
	
	Adjl **adjl = new Adjl*[n];
	int check[100] = {0};

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		if (check[i] == 0) {
			adjl[i] = new Adjl(u);
			check[i] = 1;
		}
		check[i] = 1;
		for (int j = 0; j < k; j++) {
			int vk;
			cin >> vk;
			if (check[vk - 1] == 0) {
				adjl[vk - 1] = new Adjl(vk);
				check[vk - 1] = 1;
			}
			adjl[i]->setV(k, adjl[vk - 1]);
		}
	}

	for (int i = 1; i <= n; i++) {
		adjl[0]->print(i);
	}

	delete[] adjl;
	return 0;
}

C++: #include <cstdint>
#include <queue>
#include <vector>

using namespace std;

#define GRAPH_SIZE 101
#define START_INDEX 1

enum color_t {
  WHITE,
  GRAY,
  BLACK,
};

struct data_t {
  uint32_t index;
  vector<uint32_t> connection;
  uint32_t distance;
};

static vector<uint32_t> graph[GRAPH_SIZE];
static color_t state[GRAPH_SIZE];

void breadth_first_search(void (*callback)(uint32_t, uint32_t))
{
  for (uint32_t i = START_INDEX; i < GRAPH_SIZE; i++) {
    state[i] = WHITE;
  }

  queue<data_t> queue;

  data_t data;
  data.index = START_INDEX;
  data.connection = graph[START_INDEX];
  data.distance = 0;

  queue.push(data);
  state[START_INDEX] = GRAY;

  while (!queue.empty()) {
    data_t top = queue.front();
    queue.pop();

    state[top.index] = BLACK;
    callback(top.index, top.distance);

    for (uint32_t i = 0; i < top.connection.size(); i++) {
      if (state[top.connection[i]] == WHITE) {
        data_t data;
        data.index = top.connection[i];
        data.connection = graph[top.connection[i]];
        data.distance = top.distance + 1;
        queue.push(data);
        state[data.index] = GRAY;
      }
    }
  }
}

#include <iostream>

int32_t distances[GRAPH_SIZE];

static void callback(uint32_t index, uint32_t distance)
{
  distances[index] = distance;
}

int32_t main()
{
  uint32_t num;
  cin >> num;

  for (uint32_t i = START_INDEX; i < START_INDEX + num; i++) {
    distances[i] = -1;
  }

  for (uint32_t i = 0; i < num; i++) {
    uint32_t index, len;
    cin >> index >> len;
    for (uint32_t j = 0; j < len; j++) {
      uint32_t val;
      cin >> val;
      graph[index].push_back(val);
    }
  }

  breadth_first_search(callback);

  for (uint32_t i = START_INDEX; i < START_INDEX + num; i++) {
    cout << i << " " << distances[i] << endl;
  }

  return 0;
}