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 <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++){ 
		if(dist[i] == INF)dist[i] = -1;

		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;
}

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

static int INFTY = (1<<21);
int n, M[100][100];
int d[100];

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++) {
        if (d[i] == INFTY) d[i] = -1;
        cout << i + 1 << " " << d[i] << endl;
    }
}

int main () {
    int u, k, v;
    cin >> n;

    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 <bits/stdc++.h>
using namespace std;
typedef long long ll;
using Graph = vector<vector<int>>;

int main(void)
{
	// 頂点数と辺数
	int N;
	cin >> N;

	Graph G(N + 1);
	for (int i = 1; i <= N; i++)
	{
		int u, k, v;
		cin >> u >> k;
		for (int i = 0; i < k; i++)
		{
			cin >> v;
			G[u].push_back(v);
		}
	}

	// BFSのためのデータ構造
	vector<int> dist(N + 1, -1); // 全頂点を未訪問に初期化
	queue<int> que;

	// 初期条件
	dist[1] = 0;
	que.push(1); // 0を橙色頂点に

	// BFS開始
	while (!que.empty())
	{
		int v = que.front();
		que.pop();

		// vから辿れる頂点をすべて探索
		for (int nv : G[v])
		{
			if (dist[nv] != -1) continue; // 発見済みの頂点は探索しない

			//　新たな白色頂点 nv について距離情報を更新しキューに追加
			dist[nv] = dist[v] + 1;
			que.push(nv);
		}
	}

	// 結果出力 (各頂点の頂点 0 からの距離を見る)
	for (int v = 1; v <= N; ++v) cout << v << " " << dist[v] << endl;
}

C++: #include <iostream>
#include<string>
#include<cmath>
#include<algorithm>
#include<cctype>
#include<queue>
#include<stack>
#include<stdio.h>
#include<vector>
#include<set>
#include<map>
#include<array>
#include<iomanip>
#define rep(i,n) for(int i=0;i<n;i++)
using namespace std;
static const int N=100;
static const int inf=(1<<29);
int M[N][N];
int d[N];
int n;

void dfs(int u){
    rep(i,n)d[i]=inf;
    
    queue<int> q;
    q.push(u);
    d[u]=0;
    int l;
    while(!q.empty()){
        l=q.front();
        q.pop();
        for(int v=0;v<n;v++){
            if(M[l][v]==0)continue;
            if(d[v]!=inf)continue;
            d[v]=d[l]+1;
            q.push(v);
        }
    }
    
    rep(i,n){
        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++){
            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;
        }
    }
    dfs(0);
    
}

C++: #include <bits/stdc++.h>
#define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i < (n + 1); ++i)
using namespace std;
using ll = long long;
const int INF = +100100100;
// typedef pair<int,int> P;

vector<int> D(150, INF);
vector<vector<int>> M(150, vector<int>(150));
int n;

void bfs()
{
    int s = 0;
    queue<int> Q;
    Q.push(s);
    D[0]=0;
    while (!Q.empty())
    {
        int u = Q.front();
        Q.pop();
        rep(v, n)
        {
            // 訪れたことがない
            if (D[v] == INF&&M[u][v]==1)
            {
                D[v] = D[u] + 1;
                Q.push(v);
            }
        }
    }
    rep(i,n)if(D[i]==INF)D[i]=-1;
}

int main()
{
    cin >> n;
    vector<list<int>> L(n);
    rep(i, n)
    {
        int u, e;
        cin >> u >> e;
        rep(j, e)
        {
            int v;
            cin >> v;
            --v;
            L[i].push_back(v);
        }
    }
    
    rep(i, n)
    {
        rep(j, n)
        {
            list<int>::iterator it = find(L[i].begin(), L[i].end(), j);
            if (it != L[i].end())
            {
                M[i][j] = 1;
                L[i].erase(it);
            }
        }
    }
    bfs();
    rep(i,n){
        printf("%d %d\n",i+1,D[i]);
    }
    return 0;
}