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>

using namespace std;

#define N_MAX 100

int Adj[N_MAX][N_MAX] = {};
int Min_d[N_MAX];

void bfs(int v, int d, int num_node);

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

    cin >> n;

    for (i = 0; i < n; i++) Min_d[i] = -1;

    //??£??\???????????????
    for (i = 0; i < n; i++) {
        cin >> u >> k;
        while (k-- > 0) {
            cin >> v;
            Adj[u-1][v-1] = 1;
        }
    }
/*
    cout << "show Adjacency matrix" << endl;
    for (i = 0; i < n; i++) {
        for (j = 0; j < n ; j++) {
            if (j == n - 1)
                cout << Adj[i][j] << endl;
            else
                cout << Adj[i][j] << ' ';
        }
    }
*/
    //??¢?´¢??????
    Min_d[0] = 0;
    bfs(1, 1, n);

    //????????????
    for(i = 1; i <= n; i++) {
        cout << i << ' ' << Min_d[i-1] << endl;
    }

    return 0;
}

void bfs(int v, int d, int num_node) {
    int i;
//    cout << "bfs node : " << v << endl;

    for(i = 1; i <= num_node; i++) {
        if (Adj[v-1][i-1] == 1) {
            if (Min_d[i-1] == -1 || Min_d[i-1] > d) {
                Min_d[i-1] = d;
                bfs(i, d+1, num_node);
            }
        }
    }
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;
vector<int> G[110], d(110);

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

    for (int i = 0; i < n; i++) d[i] = -1;

    queue<int> que;
    que.push(0);
    d[0] = 0;
    while (!que.empty()) {
        int u = que.front(); que.pop();
        for (int v: G[u]) {
            if (d[v] == -1) {
                que.push(v);
                d[v] = d[u] + 1;
            }
        }
    }

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

C++: #include <bits/stdc++.h>
typedef long long ll;
typedef unsigned long long ull;
#define reps(i,s,n) for(int (i)=(s);(i)<(n);++(i))
#define rep(i,n) reps(i,0,n)
#define reptr(i,n) for(int (i)=(n);(i)>=0;--(i))
#define All(x) (x).begin(),(x).end()
const ll MOD=1e9+7;
using namespace std;

vector<int> ans;
int state[105][105]={};
int n;
void bfs(int s){
  queue<int> q;
  q.push(s);
  while(!q.empty()){
    int u=q.front();
    q.pop();
    for(int v=0;v<n;v++){
      //隣接していない
      if(state[u][v]==false) continue;
      //既に探索されている
      if(ans[v]!=INT_MAX) continue;
      //未探索の場合
      ans[v] = ans[u]+1;
      q.push(v);
    }
  }

  rep(i,n){
    if(ans[i]==INT_MAX) ans[i] = -1;
    cout << i+1 << " " << ans[i] << endl;
  }
}

int main(){
  cin >> n;
  ans.resize(n,INT_MAX);
  ans[0]=0;
  rep(i,n){
    int u,k;
    cin >> u >> k;
    u--;
    rep(j,k){
      int v;
      cin >> v;
      v--;
      state[u][v]=1;
    }
  }
  bfs(0);
}

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

int n;

int V[100][100];
int D[100];
int d = 0;

std::queue<int> Q;

void bfs(int r) {
    Q.push(r);
    D[r] = 0;
    while (Q.size()) {
        r = Q.front();
        Q.pop();
        for (int i = 0; i < n; i++) {
            if ((D[i] == 0) && (V[r][i] == 1)) {
                Q.push(i);
                D[i] = D[r] + 1;
            }
        }
    }
}


int main() {
    std::cin >> n;
    for (int i = 0; i < n; i++) {
        int id, e_num;
        std::cin >> id >> e_num;
        for (int j = 0; j < e_num; j++) {
            int t;
            std::cin >> t;
            V[id - 1][t - 1] = 1;
        }
    }

    bfs(0);
    for (int i = 0; i < n; i++) {
        std::cout << i + 1 << " " << D[i] << std::endl;
    }
}

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

using namespace std;
using Graph = vector<vector<int>>;

int main() {

    int n; cin >> n;
    int u, k;

    Graph G(n+1);
    for ( int i = 1; i <= n; ++i ) {
        cin >> u >> k;
        for ( int j = 1; j <= k; ++j ) {
            int a;
            cin >> a;
            G[i].push_back(a);
            //G[b].push_back(a);
        }
    }

    /*for ( int i = 1; i <= n; ++i ) {
        for ( int ax : G[i] ) {
            cout << ax ;
        }
        cout << endl;
    }*/

    vector<int> dist(n+1,-1);
    queue<int> que;

    dist[1] = 0;
    que.push(1);

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

        for ( int nv : G[v] ) {
            if ( dist[nv] != -1 ) continue;
            dist[nv] = dist[v] + 1;
            que.push(nv);
        }
    }

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

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
using Graph = vector<vector<ll>>;
constexpr ll MOD = 1e9+7;
constexpr ll INF = 1ll<<60;

int main(int argc, char **argv)
{
	ll n; cin >> n;
	Graph G(n);
	for (ll i = 0; i < n; ++i)
	{
		ll a, k; cin >> a >> k;
		--a;
		for (ll j = 0; j < k; ++j)
		{
			ll b;
			cin >> b;
			G[a].push_back(--b);
		}
	}

	vector<ll> d(n, -1);
	d[0] = 0;
	queue<ll> que;
	que.push(0);

	while (!que.empty())
	{
		ll now = que.front(); que.pop();

		for (auto &nv : G[now])
		{
			if (d[nv] != -1) continue;
			d[nv] = d[now] + 1;
			que.push(nv);
		}
	}

	for (ll i = 0; i < n; ++i)
		std::cout << i + 1 << " " << d[i] << std::endl;
}