Go: package main

import (
	"fmt"
	"os"
	"bufio"
	"strconv"
	"container/list"
)

const MaxNode int = 100

var d []int
var A [][]int
var N int
var l *list.List

func bfs(u int) {
	d[u] = 0
	l.PushBack(u)
	for ;l.Len() != 0; {
		u = l.Front().Value.(int)
		l.Remove(l.Front())
		for v:=0; v<N; v++ {
			if A[u][v] == 0 {
				continue
			}
			if d[v] != -1 {
				continue
			}
			d[v] = d[u] + 1
			l.PushBack(v)
		}
	}
}


func nextInt(scanner *bufio.Scanner) int {
	scanner.Scan()
	num, _ := strconv.Atoi(scanner.Text())
	return num
}

func print() {
	for i:=0; i<N; i++ {
		fmt.Printf("%d %d\n", i+1, d[i])
	}
}

func initVariable() {
	d = make([]int, MaxNode)
	A = make([][]int, MaxNode)
	l = list.New()
	for i:=0; i<MaxNode; i++ {
		A[i] = make([]int, MaxNode)
		d[i] = -1
	}
}


func main() {
	initVariable()
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)
	N = nextInt(scanner)
	for i:=0; i<N; i++ {
		idx := nextInt(scanner)
		cnt := nextInt(scanner)
		for j:=0; j<cnt; j++ {
			node := nextInt(scanner)
			A[idx-1][node-1] = 1 
		}
	}
	bfs(0)
	print()
}

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;
}