Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

Python: from sys import stdin
from collections import deque
n = int(stdin.readline())
M = [[0] * (n + 1) for _ in range(n + 1)]
d = [200] * (n + 1)
def bfs():
    d[1] = 0
    dq = deque()
    dq.append(1)
    while len(dq) > 0:
        u = dq.pop()
        for v in range(1, n + 1):
            if M[u][v] == 0 or d[v] != 200: continue
            d[v] = d[u] + 1
            dq.append(v)
    for i in range(1, n + 1):
        print(i, (-1 if d[i] == 200 else d[i]))
for u in range(1, n + 1):
    U = [int(j) for j in stdin.readline().split()]
    for v in U[2:]:
        M[u][v] = 1
bfs()

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

import sys
from collections import deque

UNVISITED, VISITED_IN_QUEUE, POPPED_OUT = 0, 1, 2


def generate_adj_matrix(v_info):
    for v_detail in v_info:
        v_adj_list = v_detail[2:]
        # assert len(v_adj_list) == int(v_detail[1])
        for each in v_adj_list:
            init_adj_matrix[int(v_detail[0]) - 1][int(each) - 1] = 1
    return init_adj_matrix


def graph_bfs(v_init):
    vertices_status_list[v_init] = VISITED_IN_QUEUE
    vertices_distance_list[v_init] = 0
    vertices_visit_queue.appendleft(v_init)

    while vertices_visit_queue:
        current_vertex = vertices_visit_queue.popleft()
        for v in range(1, vertices_num + 1):
            if adj_matrix[current_vertex - 1][v - 1] and vertices_status_list[v] is UNVISITED:
                vertices_status_list[v] = VISITED_IN_QUEUE
                vertices_distance_list[v] = vertices_distance_list[current_vertex] + 1
                vertices_visit_queue.appendleft(v)
        vertices_status_list[current_vertex] = POPPED_OUT
    return vertices_distance_list


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices_num = int(_input[0])
    vertices_info = list(map(lambda x: x.split(), _input[1:]))
    init_adj_matrix = [[0] * vertices_num for _ in range(vertices_num)]
    # assert len(vertex_info) == vertex_num

    # config length = (vertex_num + 1)
    vertices_visit_queue = deque()
    vertices_status_list = [UNVISITED] * vertices_num
    vertices_status_list.insert(0, -1)
    vertices_distance_list = [-1] * (vertices_num + 1)

    adj_matrix = generate_adj_matrix(vertices_info)
    ans = graph_bfs(v_init=1)
    for j in range(vertices_num):
        print(j + 1, ans[j + 1])

Python: # your code goes here
#Breadth First Search
n=int(input())
V=[]
a=[]
for i in range(n):
    V.append([int(i) for i in input().split()])
    a.append(0)
    V=sorted(V,key=lambda x:x[0])
print('1 0')
d=1
c=0
w=[0]
p=[]
while c<n and w!=[]:
    i=0
    y=[]
 #   print(c)
    while c<n and i<len(w):
        j=2
        while j<2+V[w[i]][1] and c<n:
            if a[V[w[i]][j]-1]==0:
        #        print(a)
                a[V[w[i]][j]-1]=1
                p.append([V[w[i]][j],d])
                c+=1
                y.append(V[w[i]][j]-1)
            j+=1
        i+=1
    w=y
    d+=1
p=sorted(p, key=lambda x:x[0])
#print(p)
i=2
j=0
while i <=n and j<len(p):
    while p[j][0]>i:
        print(str(i) +" -1")
        i+=1
    print(str(p[j][0])+" "+str(p[j][1]))
    i+=1
    j+=1
while i<=n:
    print(str(i)+" -1")
    i+=1

Python: N=int(input())
List = [[] for i in range(N+1)]
for i in range(N):
    l=list(map(int,input().split()))
    List[l[0]]=l[2:]
#print(List)
D=[10**9 for i in range(N+1)]

Q=[[0,1]]
for i in range(10**9):
    if len(Q)==i:
        break
    if D[Q[i][1]]==10**9:
        D[Q[i][1]]=Q[i][0]
        for j in List[Q[i][1]]:
            if D[j]==10**9:
                Q.append([Q[i][0]+1,j])
for i in range(1,N+1):
    if D[i]==10**9:
        print(i,-1)
    else:
        print(i,D[i])

Python: import collections
n = int(input())
G = []
for i in range(n):
    T = [0]*n
    G.append(T)
for i in range(n):
    L = list(map(int,input().split()))
    for j in range(2,len(L)):
        G[i][L[j]-1] += 1
d = [float('inf')]*n
q = collections.deque()
q.append(0)
d[0] = 0
while len(q) > 0:
    start = q.popleft()
    for i in range(n):
        if G[start][i] == 1:
            if d[i] == float('inf'):
                q.append(i)
                d[i] = d[start]+1
for i in range(n):
    if d[i] != float('inf'):
        print(i+1,d[i])
    else:
        print(i+1,-1)

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

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, inpput().split()[2:])) for i in range(n)]
bfs()

Python: n = int(raw_input())
  
G = [0 for i in range(n)] 
a = [[0 for i in range(n)] for j in range(n)]
dis = [99999 for i in range(n)]
dis[0] = 0
 
for i in range(n):
    G = map(int, raw_input().split())
    for j in range(G[1]):
        a[G[0]-1][G[2+j]-1] = 1
  
def bfs_visit(s):
    for k in range(n):
      if a[s][k] == 1:
       if dis[k] > dis[s]+1:
         dis[k] = dis[s]+1
         bfs_visit(k)
 
for s in range(n):
    bfs_visit(s)
for s in range(s):
    if dis[s] == 99999:
       dis[s] = -1
for s in range(n):
    print (s+1,dis[s])