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 <bits/stdc++.h>
using namespace std;

int main(){
  int n;
  cin >> n;
  
  vector<vector<int>> g(n,vector<int>());

  for (int i = 0; i < n; i++)
  {
    int u,k;
    cin >> u >> k;

    for (int j = 0; j < k; j++)
    {
      int v;
      cin >> v;
      v--;
      g[i].push_back(v);
      // g[v].push_back(i);
    }
  }

  vector<int> dist(n,-1);
  dist[0] = 0;
  queue<int> q;
  q.push(0);
  while(!q.empty()){
    int node = q.front();
    q.pop();
    for(int next:g[node]){
      if(dist[next]!=-1) continue;
      dist[next] = dist[node]+1;
      q.push(next);
    }
  }
  for (int i = 0; i < n; i++)
  {
    cout << i+1 << " " << dist[i] << endl;
  }  
}

C++: #include <algorithm>
#include <iostream>
#include <list>
#include <vector>

class TNode
{
	std::list<TNode*> FNexts;
	int  FDistance;
	bool FVisited;
public:
	TNode(int Index)
	: FDistance(-1), FVisited(false)
	{
	}
	
	int GetDistance()const {return FDistance;}
	
	void Push(TNode* New)
	{
		FNexts.push_back(New);
	}
	
	void Visit(int Distance)
	{
		if(FVisited) return;
		FDistance = Distance;
		FVisited  = true;
		for(std::list<TNode*>::iterator It = FNexts.begin(); It != FNexts.end(); ++It){
			(*It)->Visit(Distance + 1);
		}
	}
};

class TGraph
{
	std::vector<TNode*> FNodes;
	std::vector<int> FDistances;
public:
	TGraph(int Count)
	: FNodes(Count + 1), FDistances(Count + 1, -1)
	{
		for(int i = 1; i < Count + 1; ++i){
			FNodes[i] = new TNode(i);
		}
	}
	
	~TGraph()
	{
		for(unsigned int i = 1; i < FNodes.size(); ++i){
			delete FNodes[i];
		}
	}
	
	void InputNode()
	{
		int Index;
		std::cin >> Index;
		int BranchCount;
		std::cin >> BranchCount;
		for(int i = 0; i < BranchCount; ++i){
			int Target;
			std::cin >> Target;
			FNodes[Index]->Push(FNodes[Target]);
		}
	}
	
	void BreathFirstSearch()
	{
		FNodes[1]->Visit(0);
	}
	
	int Distance(int Target)const
	{
		return FNodes[Target]->GetDistance();
	}
};

int main()
{
	int Count;
	std::cin >> Count;
	TGraph Graph(Count);
	for(int i = 0; i < Count; ++i){
		Graph.InputNode();
	}
	Graph.BreathFirstSearch();
	
	for(int i = 0; i < Count; ++i){
		std::cout << i + 1 << " " << Graph.Distance(i + 1) << std::endl;
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#define rep(i, n) for(int i = 0; i < (int)(n); ++i)
#define REP(i, n) for(int i = 1; i < (int)(n); ++i)
using namespace std;

int n;
vector<vector<int>> graph(100);
queue<int> q;
vector<int> dist(100, -1);

void BFS() {
    int u = q.front();
    q.pop();
    for (int v : graph[u]) {
        if (dist[v] == -1) {
            dist[v] = dist[u] + 1;
            q.push(v);
        }
    }
    return;
}

int main() {
    cin >> n;
    rep(i, n) {
        int u, k;
        cin >> u >> k;
        rep(i, k) {
            int v;
            cin >> v;
            graph[u - 1].push_back(v - 1);
        }
    }
    
    q.push(0);
    dist[0] = 0;
    while (q.size() > 0) BFS();
    rep(i, n) cout << i + 1 << " " << dist[i] << endl;
    return 0;
}