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 <queue>

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

int M[N][N] = {0}, d[N], n;

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

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

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

  bfs();

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
main(){
queue<int> q;
int n,a,k,u,c[101],i,j;
vector<int> d[101];
cin>>n;for(i=0;i<n;i++){
cin>>u>>k;c[i+1]=-1;
d[u].resize(k);
for(j=0;j<k;j++)cin>>d[u][j];
}q.push(1),c[1]=0;
while(!q.empty()){
a=q.front(),q.pop();
for(i=0;i<d[a].size();i++)
if(d[a][i]>1&&c[d[a][i]]==-1)q.push(d[a][i]),c[d[a][i]]=c[a]+1;
}for(i=1;i<=n;i++)cout<<i<<" "<<c[i]<<endl;
}

C++: #include <bits/stdc++.h>
#define REP(i,n) for(int i=0;i<n;++i)

using namespace std;
typedef long long ll;
typedef pair<int,int> P;

vector<vector<int>> node;
vector<bool> searched;
vector<int> cost;

void solve(int index){
    cost[index]=0;
    queue<int> que; que.push(index);
    REP(i,(int)node[index].size())
    while(!que.empty()){
        int order = que.front(); que.pop();
        REP(i,(int)node[order].size()){
            if(cost[node[order][i]]==-1){
                cost[node[order][i]]=cost[order]+1;
                que.push(node[order][i]);
            }
        }
    }
}

int main(){
   int n; cin>>n;
   node.resize(n);
   cost.resize(n,-1);
   REP(i,n){
    int index,size; cin >> index >> size; index--;
    node[index].resize(size);
     REP(j,size){cin >> node[index][j];node[index][j]--;}
    sort(node[index].begin(),node[index].end());
   }
   solve(0);
   REP(i,n)
    cout<<i+1<<" "<<cost[i]<<endl;
}

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

using namespace std;

#define MAX 100

#define WHITE 0
#define GRAY 1
#define BLACK 2

int T;
int N;

int M[MAX][MAX];
int C[MAX],D[MAX];

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

    q->push(s);
    D[s] = 0;
    C[s] = GRAY;

    while(!q->empty())
    {
        int u = q->front();
        q->pop();

        for (int v = 0; v < N; v++)
        {
            if (M[u][v] && C[v] == WHITE)
            {
                C[v] = GRAY;
                D[v] = D[u] + 1;
                q->push(v);
            }
        }

        C[u] = BLACK;
    }
}

int main ()
{
    cin >> N;

    for (int i = 0; i < N; i++)
    {
        C[i] = WHITE;
        D[i] = -1;

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

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

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

/*
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            if (j > 0)
                cout << " ";
            cout << M[i][j];
        }
        cout << endl;
    }
*/
    bfs(0);

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

    return 0;
}

C++: #include <set>
#include <map>
#include <list>
#include <queue>
#include <stack>
#include <cmath>
#include <ctype.h>
#include <ctime>
#include <cstdio>
#include <vector>
#include <string>
#include <bitset>
#include <cctype>
#include <cstdlib>
#include <cstring>
#include <utility>
#include <numeric>
#include <complex>
#include <sstream>
#include <fstream>
#include <iomanip>
#include <cassert>
#include <iostream>
#include <iterator>
#include <algorithm>

using namespace std;
#define N 100
#define INF 1e9

queue<int> Q;
int n,M[N][N];
int dist[N];

void bsf(int l){
	Q.push(l);
	for(int i = 0;i < n;i++) dist[i] = INF;

	dist[l]=0;
	while(!Q.empty()){
		int u = Q.front();
		Q.pop();
		for(int i=0;i<n;i++){
			if(M[u][i] == 0)continue;
			if(dist[i] != INF)continue;
			dist[i] = dist[u] + 1;
			Q.push(i);
		}
	}

	for(int i=0;i<n;i++) cout<<i+1<<" "<<dist[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;
		}
	}
	bsf(0);
	return 0;
}