Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), -1}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}
	nodes[1].depth = 0

	walk(1, 0, &nodes)
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v\n", (*nodes[i]).id, (*nodes[i]).depth)
	}
}

var time int
var record [100][100]bool
var q Queue

func walk(nid int, from int, nodes *map[int]*node) {
	q.Enqueue((*nodes)[nid])
	for !q.IsEmpty() {
		n := q.Dequeue().(*node)
		for _, v := range n.nexts {
			n2 := (*nodes)[v]
			if n2.depth != -1 {
				continue
			}
			n2.depth = n.depth + 1
			q.Enqueue((*nodes)[v])
		}
	}
}

type node struct {
	id    int
	nexts []int
	depth int
}

// Queue is Queue
type Queue struct {
	val []interface{}
}

// Enqueue value
func (queue *Queue) Enqueue(val interface{}) {
	queue.val = append(queue.val, val)
}

// Dequeue value
func (queue *Queue) Dequeue() interface{} {
	res := queue.val[0]
	queue.val = queue.val[1:len(queue.val)]
	return res
}

// IsEmpty return true when queue is empty
func (queue *Queue) IsEmpty() bool {
	return len(queue.val) == 0
}

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

using namespace std;
static const int N = 100;
static const int INFTY = (1 << 21);

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

void bfs(int s){
  int i, u;
  queue<int> q;
  q.push(s);
  for(i=0;i<n;i++) d[i] = INFTY;
  d[s] = 0;
  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);
    }
  } // end while

  for(i=0;i<n;i++)cout << i+1 << " " << ((d[i] == INFTY)?(-1):d[i]) << endl;
  
}

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

  for(i=0;i<n;i++){
    cin >> u >> k;
    u--; // change to origin
    for(j=0;j<k;j++){
      cin >> v;
      v--;
      M[u][v] = 1;
    }
  }

  bfs(0);

  return 0;
}

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

int main(void)
{
     //??£??\??????????????£??\???????????????
    int n, k;

    cin >> n;
    vector<vector<bool> > A(n, vector<bool>(n, false));
    for(int i = 0; i < n; i++){
        cin >> k >> k;
        for(int j = 0; j < k; j++){
            int input;
            cin >> input;
            A[i][input-1] = true;
        }
    }

    vector<int> u(n, 1000000);
    u[0] = 0;

    for(int i = 0; i < n; i++){
        for(int j = 0; j < n; j++){
            if(u[j] == i){
                for(int k = 0; k < n; k++){
                    if(A[j][k] == 1) u[k] = min(i+1, u[k]);
                }
            }
        }
    }
    for(int i = 0; i < n; i++){
        if(u[i] != 1000000) cout << i + 1 << " " << u[i] << endl;
        else cout << i + 1 << " " << "-1" << endl;
    }
    return 0;

}