Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

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

using namespace std;

static const int N = 100;
static const int WHITE = 0;
static const int GREY = 1;
static const int BLACK = 2;

int n, m[N][N];
bool visited[N];
int d[N], dist;


void bfs(int i){
	queue<int> q; q.push(i);
	visited[i] = true;

	while (!q.empty()) {
		int u = q.front(); q.pop();
		for (int v = 0; v < n; ++v) {
			if (!visited[v] && m[u][v]){
				d[v] = d[u] + 1;
				visited[v] = true;
				q.push(v);
			}
		}
	}
}


void search(){
	for (int i = 0; i < n; ++i) {
		d[i] = -1;
		visited[i] = false;
	}
	d[0] = 0;
	for (int i = 0; i < n; ++i) {
		if (!visited[i]) bfs(i);
	}
	for (int i = 0; i < n; ++i)	cout << i + 1 << " " << d[i] << endl;
}


int main()
{
	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) {
		int u, d; cin >> u >> d;
		for (int j = 0; j < d; ++j) {
			int v; cin >> v;
			m[u - 1][v - 1] = 1;
		}
	}

	search();

	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];

void bfs(int s){
  queue<int> q;
  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;

  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;
    }
  }
  bfs(0);

  return 0;
}

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

int main () {
    int n ;
    cin >> n;

    vector <int> v[n + 1];

    for (int i = 1; i <= n; i++) {
        int x, no;
        cin >> x >> no;
        for(int j = 0; j < no; j++) {
            int temp;
            cin >> temp;
            v[x].push_back(temp);
        }
    }

	queue <int> q;
	q.push(1);
	
	int dis[n + 1];
	for (int i = 0; i <= n; i++)
		dis[i] = -1;
	dis[1] = 0;
		
	bool vis[n + 1] = {0};
    vis[1] = 1;
	while (!q.empty()) {
		for (int i = 0; i < v[q.front()].size(); i++) {
			int temp = v[q.front()][i];
			if (!vis[temp]) {
				q.push(temp);
				vis[temp] = 1;
				dis[temp] = dis[q.front()] + 1;
			}	
		}
		q.pop();
	}
	
	for (int i = 1; i <= n; i++)
		cout << i << ' ' << dis[i] << '\n';
}

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

int M[101][101], d[101], n;

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

	for (int i = 1; i <= n; i++)
		d[i] = -1;
}

void bfs(int x)
{
	queue<int> Q;

	Q.push(x);
	d[x] = 0;

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

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> n;
	set();

	bfs(1);

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

	return 0;
}

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

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

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

void bfs(int s)
{
    std::queue<int> q;
    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++)
    {
        std::cout << i + 1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << std::endl;
    }
}

int main() 
{
    int u, k, v ;
    std::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++)
    {
        std::cin >> u >> k ;
        u--;
        for (int j = 0; j < k; j++)
        {
            std::cin >> v ;
            v-- ;
            M[u][v] = 1 ;
        }
        
    }
    
    bfs(0) ;
    return 0 ;
}