Go: package main

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

const MAX = 1000
const NIL = -1

type Node struct {
	id    int
	depth int
}

type Queue struct {
	head      int
	tail      int
	container [MAX]Node
}

func (q *Queue) inQueue(x Node) {
	q.container[q.tail] = x
	q.tail = (q.tail + 1) % MAX
}

func (q *Queue) deQueue() Node {
	x := q.container[q.head]
	q.head = (q.head + 1) % MAX
	return x
}

func (q *Queue) isEmpty() bool {
	return q.head == q.tail
}

var sc = bufio.NewScanner(os.Stdin)

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func main() {
	n := scanInt()
	route := make([][]int, n)
	for i := range route {
		u, k := scanInt(), scanInt()
		u--
		route[u] = make([]int, k)
		for j := range route[u] {
			num := scanInt()
			num--
			route[i][j] = num
		}
	}

	d := make([]int, n)
	for i := range d {
		d[i] = NIL
	}

	start := Node{0, 0}
	que := Queue{}
	que.inQueue(start)
	for !que.isEmpty() {
		node := que.deQueue()
		if d[node.id] != NIL {
			continue
		}
		d[node.id] = node.depth

		for _, nextId := range route[node.id] {
			next := Node{id: nextId, depth: node.depth + 1}
			que.inQueue(next)
		}
	}

	for i, depth := range d {
		fmt.Println(i+1, depth)
	}
}

Python: from collections import deque

N = int(input())                            # 頂点数

conj = [[] for _ in range(N)]
for i in range(N):                          # 各頂点での進める先の候補の集合
    L = list(map(int, input().split()))
    for a in L[2:]:
        conj[i].append(a-1)         # 頂点番号をデクリメント

start = 0

visit = [False]*N                           # 訪れたかどうかをメモ
second_visit = [False]*N                    # 二度目に訪れた事をメモ
next_set = deque()                          # 次に進む候補を列挙する。スタック（右から取り出す = pop）だと深さ優先になり、キュー（左から取り出す = popleft）だと幅優先になる
next_set.append((start, 0))                 # スタート地点を決める。第二成分は時刻を表す。
visit[start] = True                         # スタート地点は最初から踏んでいる。
res = [-1 for _ in range(N)]
res[0] = 0

while next_set:                             # p = [] になったら止める
    p, t = next_set.popleft()               # 要素を消去して、消去した要素を出力
    for q in conj[p]:                       # 頂点 p から進める経路の候補から一つ選ぶ
        if not visit[q]:                    # 訪れた事がない場所のみ進む。壁などの条件がある場合は、ここに " grid[p] != 壁 " 等を追加する
            visit[q] = True                 # 頂点 q に一度訪れた事をメモ (for の前に書くと、ここで選ばれた q が最短であるはずなのに、違う経路でvisit = Trueを踏んでしまう可能性がある)
            res[q] = t + 1
            next_set.append((q, t + 1))     # p から q へと移動。時刻を 1 進める


for i in range(N):
    print(i+1, res[i])

Python: from collections import deque
n = int(input())
A = [0]*(n+1)
D = [0]*(n+1)
DP = [0]*(n+1)
d = deque()
for i in range(n):
    A[i+1] = [int(i) for i in input().split()]
d.append(1)
DP[1]=0
while(len(d)>0):
    tmp = d.pop()
    for i in A[tmp][2:]:
        if not DP[i]:
            D[i] = D[tmp]+1
            DP[i] = 1
            d.appendleft(i)
for i in range(1,n+1):
    tmp = "{} {}".format(i,D[i])
    print(tmp)

Python: import sys
import math
import string
import fractions
import random
from operator import itemgetter
import itertools
from collections import deque
import copy
import heapq
import bisect

MOD = 10 ** 9 + 7
INF = float('inf')
input = lambda: sys.stdin.readline().strip()

sys.setrecursionlimit(10 ** 8)

n = int(input())
dis = [-1] * n
info = [list(map(int, input().split())) for _ in range(n)]

stack = [[0, 0]]
ans = 0
while len(stack) > 0:
    num = stack.pop(0)
    if dis[num[0]] == -1:
        dis[num[0]] = num[1]
    for i in info[num[0]][2:]:
        if dis[i-1] == -1:
            stack.append([i - 1, num[1] + 1])
for i in range(n):
    print(str(i+1) + " " + str(dis[i]))

Python: n=int(input())
ne=[[] for _ in range(n+1)]
for _ in range(n):
    u,k,*v=map(int,input().split())
    ne[u]=v
dis=[-1]*(n+1)
dis[1]=0
q=[1]
while q:
    p=q.pop(0)
    for e in ne[p]:
        if dis[e]==-1:
            dis[e]=dis[p]+1
            q.append(e)
for i in range(1,n+1):
    print(i,dis[i])

Python: from collections import deque
Q=deque()
n=int(input())
graph={}
d=[0 for i in range(n+1)]

for i in range(n):
    tmp=list(map(int,input().split()))
    graph[tmp[0]]=[0 for j in range(n+1)]
    for j in range(tmp[1]):
        graph[tmp[0]][tmp[2+j]]=1

Q.append(1)
while len(Q) is not 0:
    number=Q[0]
    if 1 in graph[number]:
        for i in range(graph[number].count(1)):
            Q.append(graph[number].index(1))
            if d[graph[number].index(1)] is 0:
                d[graph[number].index(1)]=d[number]+1
            graph[number][graph[number].index(1)]=0
        
    Q.popleft()

for i in range(n):
    if i==0:
        print(i+1,0)
    else:
        if d[i+1]==0:
            print(i+1,-1)
        else:
            print(i+1,d[i+1])

Python: def srch(i, l, Lng, Dst):
    if Lng[i] > l:
        Lng[i] = l

    if Dst[i] is not None and len(Dst[i]) > 0:
        while len(Dst[i]):
            c = Dst[i].pop()
            srch(c,l+1, Lng, Dst)

def main():
    num = int(input())
    Dst = [None for i in range(num + 1)]
    Lng = [999] * (num + 1)
    
    for n in range(1, num+1):
        a = list(map(int,input().split()))
        u = a[0]
        if a[1] > 0:
            Dst[u] = a[2:]

    srch(1, 0, Lng, Dst)

    for n in range(1, num+1):
        l = Lng[n]
        if l > num:
            l = -1
        print("{} {}".format(n,l))

if __name__ == '__main__':
    main()

Python: if __name__ == '__main__':
    n = int(input())
    graph = [[0 for i in range(n)] for _ in range(n)]
    frist = [0 for _ in range(n)]
    end = [0 for _ in range(n)]
    visit = [False for _ in range(n)]
    # get the group
    for i in range(n):
        datas = [int(num) for num in input().split(' ')]
        if datas[1] > 0:
            for j in datas[2:]:
                graph[datas[0] - 1][j - 1] = 1

    queue = [0]
    visit = [False for _ in range(n)]
    visit[0] = True
    depths = [0 for _ in range(n)]
    while len(queue) != 0:
        point = queue.pop(0)
        for i in range(n):
            if graph[point][i] == 1 and visit[i] is False:
                queue.append(i)
                visit[i] = True
                depths[i] = depths[point] + 1
        if len(queue) == 0:
            for i in range(n):
                if visit[i] is False:
                    queue.append(i)
                    depths[i] = -1
                    visit[i] = True

    for i in range(n):
        print('%d %d' % (i + 1, depths[i]))

Python: import collections
N = int(input())
P = [[0 for _ in range(N)] for _ in range(N)] 
for i in range(N):
    u,k,*varray = map(int,input().split()) # u,k は数, varray は配列
    for v in varray:
        P[u-1][v-1] = 1    

D = [-1 for _ in range(N)]
D[0] = 0 # 始点への距離は 0, 他の距離は-1
Q = collections.deque()
Q.append(0)
while len(Q) > 0:
    c = Q.popleft()
    for i in range(N):
        if P[c][i]==1 and D[i]==-1:
            D[i] = D[c]+1
            Q.append(i)
for v in range(N):
    print(v+1, D[v])

Python: from collections import deque

n = int(input())
G = []
checked = [False for i in range(n + 1)]
d = [-1 for i in range(n + 1)]
G.append([])
for i in range(n):
    u, k, *v = map(int, input().split())
    G.append(v)

q = deque()
q.append(1)
d[1] = 0

while q:
    current = q.pop()
    for adj in G[current]:
        if not checked[adj]:
            q.append(adj)
            checked[adj] = True
            d[adj] = d[current] + 1

for id in range(1, n + 1):
    print("{0} {1}".format(id, d[id]))