Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Queue struct {
	arr []int
}

func (q *Queue) push(v int) {
	q.arr = append(q.arr, v)
}

func (q *Queue) pop() int {
	res := q.arr[0]
	q.arr = q.arr[1:]
	return res
}

func (q *Queue) isEmpty() bool {
	return len(q.arr) == 0
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	var q Queue
	seen := make([]int, N)
	for i := 0; i < N; i++ {
		seen[i] = -1
	}
	var search func(cur int)
	search = func(cur int) {
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if seen[next] == -1 {
				q.push(next)
				seen[next] = seen[cur] + 1
			}
		}
	}
	q.push(0)
	seen[0] = 0
	for !q.isEmpty() {
		search(q.pop())
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i+1, seen[i])
	}
	wtr.Flush()
}

C++: #include <bits/stdc++.h>
#define rep(i, a, b) for (int i = a; i < (b); i++)
#define rrep(i, a, b) for (int i = a; i >= (b); i--)
#define all(x) (x).begin(), (x).end()
using namespace std;
using ll = long long;
using P = pair<int, int>;
template <class T>
inline bool chmin(T& a, T b) {
   if (a > b) {
      a = b;
      return true;
   }
   return false;
}
template <class T>
inline bool chmax(T& a, T b) {
   if (a < b) {
      a = b;
      return true;
   }
   return false;
}
void hr() {
   cerr << "--------------" << endl;
}
const int INF = 1001001001;
const int MOD = 1000000007;

vector<int> to[100];
int main() {
   cin.tie(0);
   ios_base::sync_with_stdio(0);

   int n;
   cin >> n;
   rep(i, 0, n) {
      int u, k;
      cin >> u >> k;
      u--;
      rep(i, 0, k) {
         int v;
         cin >> v;
         v--;
         to[u].push_back(v);
      }
   }
   queue<int> que;
   vector<int> d(n, -1);
   que.push(0);
   d[0] = 0;
   while (que.size()) {
      int u = que.front();
      que.pop();
      for (auto v : to[u]) {
         if (d[v] < 0) {
            d[v] = d[u] + 1;
            que.push(v);
         }
      }
   }
   rep(i, 0, n) printf("%d %d\n", i + 1, d[i]);
   return 0;
}

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

static const int N = 100;
static const int INF = 100000000000;

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


void bfs(int s) {
	

	queue<int> q;
	q.push(s);
	
	for (int i=0; i< n;i++)d[i] = INF;
	d[s] = 0;
	int u;

	while (!q.empty()) {
		u = q.front(); q.pop();
		for(int v=0;v<n;v++){
			if (Adj[u][v] == 0) continue;
			if (d[v] != INF) continue;
			d[v] = d[u] + 1;
			q.push(v);
			}
		}
	for (int i = 0; i < n; i++) {
		cout << i + 1 << " " << ((d[i] == INF) ? (-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++) {
			Adj[i][j] = 0;
		}
	}
	for (int i = 0; i < n; i++) {
		cin >> u >> k;
		u--;
		for (int j = 0; j < k; j++) {
			cin >> v;
			v--;
			Adj[u][v] = 1;
		}
	}
	
	bfs(0);
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

int G[110][110];
bool seen[110];
int d[110];
int N;

struct MyQueue{
    int num[110];
    int head = 0;
    int tail = 0;

    void enqueue( int n ){
        num[tail++] = n;
    }

    int dequeue(){
        return num[head++];
    }

    bool empty(){
        return head == tail;
    }
};

int main(){
    cin >> N;
    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--;
            G[u][v] = 1;
        }
    }

    MyQueue que;
    que.enqueue( 0 );
    seen[0] = 1;
    while( !que.empty() ){
        int u = que.dequeue();
        for( int v = 0; v < N; v++ ){
            if( G[u][v] && !seen[v] ){
                que.enqueue( v );
                d[v] = d[u] + 1;
                seen[v] = 1;
            }
        }
    }

    for( int i = 1; i < N; i++ ){
        if( d[i] == 0 ) d[i] = -1;
    }

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

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;
}