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<iostream>
#include<queue>
using namespace std;
#define MAX 100
#define NIL -1

int n, T[MAX+1][MAX+1], d[MAX+1];
string color[MAX+1];
queue<int> Q;

void search(int u){
  Q.push(u);
  while(!Q.empty()){
    u = Q.front();
    color[u] = "black";
    for ( int i = 1; i <= n; i++){
      if ( T[u][i] && color[i] == "white"){
        if ( d[u] != NIL){
          d[i] =  d[u] + 1;
          color[i] = "brown";
        }
        Q.push(i);
      }
    }
    Q.pop();
  }
}

int main(){
  cin >> n;

  //init
  for ( int i = 1; i <= n; i++){
    color[i] = "white";
    d[i] = NIL;
    for ( int j = 0; j <= n; j++){
      T[i][j] = 0;
    }
  }

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

  d[1] = 0;
  for ( int i = 1; i <= n; i++){
    search(i);
  }

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

  return 0;
}

C++: #line 1 "test/ALDS1_11_C.test.cpp"
#define PROBLEM "http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C&lang=ja"
#line 1 "macro/macros.hpp"



#include <bits/stdc++.h>
using namespace std;
#define rep(i,N) for(int i=0;i<int(N);++i)
#define rep1(i,N) for(int i=1;i<int(N);++i)
#define all(a) (a).begin(),(a).end()
#define print(v) { cerr<<#v<<": [ "; for(auto _ : v) cerr<<_<<", "; cerr<<"]"<<endl; }
#define printpair(v) { cerr<<#v<<": [ "; for(auto _ : v) cerr<<"{"<<_.first<<","<<_.second<<"}"<<", "; cerr<<"]"<<endl; }
#define dump(x) cerr<<#x<<": "<<x<<endl;
#define bit(k) (1LL<<(k))
#define Yes "Yes"
#define No "No"
#define YES "YES"
#define NO "NO"
typedef long long ll;

template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 >& p) {
  os << "{" <<p.first << ", " << p.second << "}";
  return os;
}
template <class T> using vec = vector<T>;
template <class T> using vvec = vector<vec<T>>;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }

const int INF = (ll)1e9;
const ll INFLL = (ll)1e18+1;
const ll MOD = (ll)1e9+7;

const double PI = acos(-1.0);

const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
const string dir = "DRUL";


#line 1 "graph/template.hpp"


#line 4 "graph/template.hpp"

template<typename T = int>
struct edge{
    int to;
    T cost;
    int id;
    edge(int _to, T _cost = 1, int _id = -1) :to(_to), cost(_cost), id(_id) {}
};

template<class T>
class Graph {
  public:
    int N;
    vvec<edge<T>> G;
    Graph(int _N): N(_N),G(_N){
    }
    void add_Directed_edge(int from, int to, T cost = 1, int id = -1){
        G[from].push_back({to, cost, id});
    }
    void add_edge(int v1, int v2, T cost = 1, int id = -1){
        add_Directed_edge(v1, v2, cost, id);
        add_Directed_edge(v2, v1, cost, id);
    }
    //standard input
    void input(int M, int padding = -1, bool weighted = false, bool directed = false){
        rep(i,M){
            int a, b;
            cin >> a >> b;
            a += padding;
            b += padding;
            T c = T(1);
            if(weighted)cin >> c;
            if(directed)add_Directed_edge(a,b,c);
            else add_edge(a,b,c);
        }
    }
};

#line 1 "graph/shortest_path/bfs.hpp"


#line 5 "graph/shortest_path/bfs.hpp"

template<typename T>
class BFS : public Graph<T>{
  public:
    using Graph<T>::Graph;
    int N;
    vec<T> d;
    BFS(int _N):N(_N), Graph<T>::Graph(_N), d(_N,-1){
    }
    vec<T> bfs(int start = 0){
        auto edges = Graph<T>::G;
        queue<int> q;
        q.push(start);
        d[start] = 0;
        while(!q.empty()){
            int cur = q.front(); q.pop();
            for(auto nv: edges[cur]){
                if(d[nv.to] != -1)continue;
                d[nv.to] = d[cur] + 1;
                q.push(nv.to);
            }
        }
        return d;
    }
};

#line 5 "test/ALDS1_11_C.test.cpp"

int main(){
    int N;
    cin >> N;
    BFS<int> G(N);
    rep(i,N){
        int u, k;
        cin >> u >> k;
        u--;
        rep(j,k){
            int v;
            cin >> v;
            v--;
            G.add_Directed_edge(u, v);
        }
    }
    G.bfs();
    rep(i,N){
        cout << i + 1 << " " << G.d[i] << endl;
    }
}