Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	g := make([][]int, n+1)
	d := make([]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

	for i := 1; i <= n; i++ {
		fmt.Printf("%d %d\n", i, d[i])
	}
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<utility>
#include<numeric>
#include<vector>
#include<map>
#include<set>
#include<tuple>
#include<stack>
#include<queue>
#include<functional>
#include<iterator>
#include<cmath>

using namespace std;

typedef pair<int,int> P;


int main(){
	int n;
	cin >> n;

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

	int d[n];
	fill(d,d+n,-1);
	queue<P> que;
	que.push(P(0,0)); //点番号（0オリジン）、距離
	d[0] = 0;
	while(!que.empty()){
		P t = que.front(); que.pop();
		for(int i=0;i<es[t.first].size();i++){
			if(d[es[t.first][i]] == -1){
				que.push(P(es[t.first][i],t.second+1));
				d[es[t.first][i]] = t.second+1;
			}
		}
	}

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

C++: #include <algorithm>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

using namespace std;

typedef long long ll;

#define MOD 1000000007

vector<int> g[100];

int main() {
  int n;
  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].push_back(v);
    }
  }
  vector<int> d(n, 1e9);
  queue<int> que;
  que.push(0);
  d[0] = 0;
  while (!que.empty()) {
    int v = que.front();
    que.pop();
    for (auto u : g[v]) {
      if (d[u] == 1e9) {
        que.push(u);
        d[u] = d[v] + 1;
      }
    }
  }
  for (int i = 0; i < n; ++i) {
    cout << i + 1 << " " << (d[i] == 1e9 ? -1 : d[i]) << endl;
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll INF = 1e18;
const ll mod = 1000000007;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
template<class T> inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template<class T> inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int ctoi(char c) {
  if (c >= '0' && c <= '9') {
    return c - '0';
  }
  return 0;
}
ll factorial(ll n) {
  if (n == 1) {
    return 1;
  }
  ll ans = factorial(n-1);
  return ans*n;
}
ll gcd(ll a, ll b) {
  if (a < b) {
    ll tmp = a;
    a = b;
    b = tmp;
  }
  ll r = a%b;
  while(r != 0) {
    a = b;
    b = r;
    r = a%b;
  }
  return b;
}
ll lcm(ll a, ll b) {
  return (a/gcd(a, b))*b;
}

int main() {
  ll n;
  cin >> n;
  vector <vector <bool>> v(n, vector <bool> (n, 0));
  vector <ll> color(n, 0);
  vector <ll> d(n, INF);
  queue <ll> q;
  rep(i, n) {
    ll a, b, c;
    cin >> a >> b;
    rep(j, b) {
      cin >> c;
      v.at(a-1).at(c-1) = 1;
    }
  }
  color.at(0) = 1;
  d.at(0) = 0;
  q.push(0);
  while (!q.empty()) {
    ll i = q.front();
    q.pop();
    rep(j, n) {
      if (v.at(i).at(j) && color.at(j)==0) {
        color.at(j) = 1;
        d.at(j) = d.at(i) + 1;
        q.push(j);
      }
    }
    color.at(i) = 2;
  }
  rep(i, n) {
    if (d.at(i) == INF) {
      cout << i+1 << ' ' << -1 << endl;
    } else {
      cout << i+1 << ' ' << d.at(i) << endl;
    }
  }
}

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

using namespace std;

int main(){
  queue<int> q;
  int n,k,u;
  int c[101];
  vector<int>  d[101];
  cin>>n;
  for(int i=0;i<n;i++){
    cin>>u>>k;
    d[u].resize(k);
    for(int j=0;j<k;j++) cin>>d[u][j];
  }
  for(int i=0;i<=n;i++) c[i]=-1;
  q.push(1);
  c[1]=0;
  int a;
  while(!q.empty()){
    a=q.front(),q.pop();
    for(int 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(int i=1;i<=n;i++) cout<<i<<" "<<c[i]<<endl;
  return 0;
}

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

struct Node {
	int d = -1;
	bool flag = false;
	vector<int> v;
};

queue<int> s;

void bfs_s(vector<Node>& u, int id, int d)
{
	if (u[id].flag) return;

	u[id].d = d;
	u[id].flag = true;
	for (int i = 0; i < u[id].v.size(); i++)
	{
		s.push(u[id].v[i]);
	}
	return;
}

void bfs(vector<Node>& u)
{
	int d = 0;
	while(!s.empty())
	{
		int n = s.size();
		for (int i = 0; i < n; i++)
		{
			bfs_s(u, s.front(), d);
			s.pop();
		}
		d++;
	}
	return;
}

int main(void)
{
	int N, id, k, x;
	Node z;
	cin >> N;
	vector<Node> u(N + 1);
	for (int i = 0; i < N; i++)
	{
		cin >> id >> k;
		for (int j = 0; j < k; j++)
		{
			cin >> x;
			u[id].v.push_back(x);
		}
	}
	s.push(1);
	bfs(u);

	for (int i = 1; i <= N; i++) cout << i << " " << u[i].d << endl;

	return 0;
}

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

using namespace std;

vector<int> graph[100];
int dist[100]={0};
int main(){
  int n;
  cin >> n;

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

  queue<int> q;
  q.push(0);
  dist[0] = 0;
  while(!q.empty()){
    auto v = q.front();q.pop();
    for(auto next_v:graph[v]){
      if(dist[next_v]==-1){
        dist[next_v] = dist[v]+1;
        q.push(next_v);
      }
    }
  }
  for(int i=0;i<n;++i){
    cout << i+1 << " " << dist[i] << endl;
  }
}

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

#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP0(i,n) for(int i=0, i##_len=(n); i<i##_len; ++i)
#define REP1(i,n) for(int i=1, i##_len=(n); i<=i##_len; ++i)
#define RREP0(i,n) for(int i=n-1; i>=0; --i)
#define RREP1(i,n) for(int i=n; i>=1; --i)

#define SORT(c) sort((c).begin(),(c).end())
#define whole(f,x,...) ([&](decltype((x)) whole) { return (f)(begin(whole), end(whole), ## __VA_ARGS__); })(x)
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define CLR(a) memset((a), 0 ,sizeof(a))

inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

typedef long long LL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;

const int INTINF = 2147483647;
const LL LLINF = 9223372036854775807;
const double EPS = 1e-10;
const double PI  = acos(-1.0);
#define N 100

int gcd(int a,int b){return b?gcd(b,a%b):a;}
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};

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


void bfs(int s) {
  queue<int> Q;
  Q.push(s);
  REP0(i,n) d[i]=INTINF;
  d[s]=0;
  int u;
  while ( !Q.empty() ) {
    u = Q.front(); Q.pop();
    REP0(v,n){
      if (M[u][v]==0 || d[v]!=INTINF) continue; //disconnected or visited
      d[v] = d[u]+1;
      Q.push(v);
    }
  }
  REP0(i,n){
    std::cout << i+1 << " " << ( (d[i]==INTINF) ? (-1) : d[i] ) << '\n';
  }
}


void input(){
  std::cin >> n;
  int v1, v2, d;
  REP0(i,n) { REP0(j,n) M[i][j]=0; }
  REP0(i,n){
    std::cin >> v1 >> d;
    REP0(j,d){
      std::cin >> v2; M[v1-1][v2-1]=1;
    }
  }
}


int main(int argc, char const *argv[]) {
  cin.tie(0); ios::sync_with_stdio(false);
  input();
  bfs(0);
  return 0;
}