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: # -*- coding: utf-8 -*-
from collections import deque


if __name__ == '__main__':

    n = int(input())
    M = [[0 for i in range(n)] for j in range(n)]
    for _ in range(n):
        l = list(map(int, input().split(" ")))
        u = l[0]
        k = l[1]
        if k != 0:
            for v in l[2:]:
                M[u - 1][v - 1] = 1

    color = [0] * n
    d = [float("inf")] * n
    Q = deque()

    def bfs(s):  # breadth-first search
        color[s] = 1
        d[s] = 0
        Q.append(s)

        while len(Q) != 0:
            u = Q.popleft()
            for v in range(n):
                if M[u][v] == 1 and color[v] == 0:
                    color[v] = 1
                    d[v] = d[u] + 1
                    Q.append(v)
            color[u] = 2

    bfs(0)
    for i in range(n):
        print(i + 1, d[i])

Python: n=int(input())
G=[[0,[],0,-1]]
for i in range(n):
    v=[int(j) for j in input().split(" ")]
    u=v.pop(0)
    k=v.pop(0)
    G.append([k,v,0,-1])





distance=0
dis_list=[1]
G[1][3]=0
G[1][2]=1
while len(dis_list)!=0:
    distance+=1
    dis_list_cash=[]
    for i in dis_list:
        k=G[i][0]
        v=G[i][1]
        for j in range(k):
            if G[v[j]][2]==0:
                G[v[j]][2]=1
                G[v[j]][3]=distance
                dis_list_cash.append(v[j])
    
    dis_list=dis_list_cash



for i in range(1,n+1):
    print(str(i)+" "+str(G[i][3]))

Python: n = int(input())
E = [[]]*n

for i in range(n):
    inputs = list(map(int, input().split()))
    if inputs[1]>0:
        for e in inputs[2:]:
            E[i] = E[i] + [e-1]

visited = [-1]*n
dist = [-1]*n
dist[0] = 0

from collections import deque

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

while len(d):
    nd = d.popleft()
    #print(nd, E[nd])
    for e in E[nd]:
        #print(e)
        if visited[e]<0:
            d.append(e)
            dist[e] = dist[nd] + 1
            visited[e] = 1
    #print(d, visited, dist, len(d))
            

for i in range(n):
    print(i+1, dist[i])

Python: # vim: set fileencoding=utf-8:
import sys
import collections
INF = 10000000
queue = collections.deque()  # appendleft(), pop()
n = int(input())
graph = [[0] * (n+1) for _ in range(n+1)]
yet = [i for i in range(1, n+1)]
ans = [-1] * (n+1)
for i in range(1, n+1):
    tmp = [int(ele) for ele in input().split()]
    for adjc in tmp[2:]:
        graph[i][adjc] = 1

d = [INF] * (n+1)
d[1] = 0


def main():
    global queue, d
    queue.appendleft(1)
    bfs(queue)
    d = list(map(lambda x: -1 if x == INF else x, d))
    for i in range(1, n+1):
        print(str(i) + " " + str(d[i]))


def bfs(queue):
    global graph, yet
    if len(queue) == 0:
        return

    n = queue[-1]
    yet.remove(n)

    # 各ノードとの隣接状態をみていく
    for i, adjacency in enumerate(graph[n]):
        if adjacency == 1 and i in yet and i not in queue:  # 隣接 かつ 未探索 かつ queueにもない 待ち行列に加える
            queue.appendleft(i)
            # 隣接していれば、自分自身までの最短コストに1を加えたものとの min() を計算する
            d[i] = min(d[i], d[n] + 1)
    else:
        queue.pop()
        bfs(queue)


if __name__ == "__main__":
    main()

Python: from sys import stdin
from collections import deque
n = int(input())
d = [-1] * (n + 1)
def bfs():
    d[1] = 0
    dq = deque([1])
    while len(dq) != 0:
        v = dq.popleft()
        for c in G[v]:
            if d[c] != -1 : continue
            d[c] = d[v] + 1
            dq.append(c)
    for i, x in enumerate(d[1:], start=1):
        print(i, x)
G = [0] + [list(map(int, input().split()[2:])) for i in range(n)]
bfs()

Python: from collections import deque
n = int(input())

g = [[] for _ in range(n)]
for i in range(n):
    _, _, *edge = map(lambda x: int(x)-1, input().split())

    g[i] = edge

q = deque()
q.append(0)
dist = [-1 for _ in range(n)]
dist[0] = 0

while(len(q) > 0):
    v = q.popleft()

    for nv in g[v]:
        if(dist[nv] != -1): continue
        
        dist[nv] = dist[v] + 1
        q.append(nv)

for i in range(n):
    print(i+1, dist[i])

Python: # -*- coding: utf-8 -*-                                                                                                                                                                                                                               

def BFS(adj, start):
    n = len(adj)
    d = [-1] * n
    flag = [0] * n
    Q = []

    Q.append(start)
    d[start] = 0
    flag[start] = 1

    while len(Q) != 0:
        u = Q.pop(0)
        v = [i for i, x in enumerate(adj[u]) if (x == 1) and (flag[i] == 0)] # v <= ??£??\???????????????????????¢?´¢??????????????????
        
        for i in v:
            Q.append(i)
            d[i] = d[u] + 1
            flag[i] = 1
    
    return d

def main():
    n = int(input())
    adj = [[0 for i in range(n)] for j in range(n)]
    
    for i in range(n):
        tmp = list(map(int, input().split()))
        u = tmp[0]
        u = u -1
        k = tmp[1]
        v = tmp[2:]
        for j in range(k):
            adj[u][v[j]-1] = 1
    
    d = BFS(adj, 0)
    for i in range(n):
        print(i+1, d[i])


if __name__ == "__main__":
    main()

Python: from collections import deque
N = int(input())
g = {i: deque() for i in range(1,N+1)} #1-index
for i in range(1, N+1):
    u, k, *v = map(int, input().split())
    for j in v:
        g[u].append(j)
        
seen = [0]*(N+1) #1-index
que = deque([])
dist = [-1]*(N+1) #1-index

seen[1] = 1
que.append(1)
dist[1] = 0

while que: #queが空になるまで
    q_no = que.popleft()
    if not g[q_no]: continue #点q-noから他の点に伸びていない
    
    for next_v in g[q_no]:
        if seen[next_v] == 1: continue #訪問済
        
        seen[next_v] = 1 #訪問済にする
        dist[next_v] = dist[q_no] + 1 #距離情報を格納
        que.append(next_v) #queに追加

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

Python: from collections import deque
n=int(input())
l=[0]+[list(map(int,input().split()))[2:] for _ in range(n)]

flg=["white"]*(n+1)
dist=[-1]*(n+1)

def BFS(x):

    queue = deque([x])
    dist[x]=0
    flg[x]="gray"

    while queue:
        current=queue.popleft()
        for i in l[current]:
            if flg[i]=="white":
                queue.append(i)
                flg[i]="gray"
                dist[i]=dist[current]+1
        flg[current]="black"

BFS(1)

for num,i in enumerate(dist[1:],1):
    print(num,i)

Python: import queue
N=int(input())
M=[input().split()[2:]for _ in[0]*N]
q=queue.Queue();q.put(0)
d=[-1]*N;d[0]=0
while not q.empty():
 u=q.get()
 for v in M[u]:
  v=int(v)-1
  if d[v]<0:d[v]=d[u]+1;q.put(v)
for i in range(N):print(i+1,d[i])