Go: package main

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

type Pair struct {
	v int
	d int
}

type Queue []Pair

func (q *Queue) push(v Pair) {
	*q = append(*q, v)
}

func (q *Queue) pop() Pair {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nVerts := scanInt(sc)
	graph := make([][]int, nVerts+1)

	for i := 0; i < nVerts; i++ {
		u := scanInt(sc)
		nDegrees := scanInt(sc)

		graph[u] = make([]int, nDegrees)
		for d := 0; d < nDegrees; d++ {
			graph[u][d] = scanInt(sc)
		}
	}

	paths := make([]int, nVerts+1)

	queue := Queue(make([]Pair, 0))
	queue.push(Pair{1, 1})
	paths[1] = 1

	for len(queue) > 0 {
		p := queue.pop()
		d := p.d + 1
		for _, v := range graph[p.v] {
			if paths[v] == 0 {
				paths[v] = d
				queue.push(Pair{v, d})
			}
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= nVerts; i++ {
		fmt.Fprintf(w, "%d %d\n", i, paths[i]-1)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

Python: def BFS(G):
    ans = [0] + [[i+1,-1] for i in range(len(G))]
    def main(G,i,d):
        if -1 < ans[i][1] <= d: return
        ans[i] = [i, d]
        for j in G[i-1][2:]: main(G,j,d+1)
    main(G,1,0)
    return ans[1:]


if __name__=='__main__':
    n = int(input())
    G = [list(map(int,input().split())) for _ in range(n)]
    for out in BFS(G): print(*out)

Python: n = int(input())
 
adj = [None]
for i in range(n):
    adj_i = list(map(int, input().split()[2:]))
    adj.append(adj_i)
 
isSearched = [None] + [False] * n
 
distance = [None] + [-1] * n
 
def bfs(u):
    d = 0
    isSearched[u] = True
    distance[u] = d
    edge = [u]
    while edge:
        q = list(edge)
        edge = []
        d += 1
        for c_e in q:
            for n_e in adj[c_e]:
                if not isSearched[n_e]:
                    isSearched[n_e] = True
                    edge.append(n_e)
                    distance[n_e] = d
 
 
bfs(1)
 
for i, x in enumerate(distance[1:], start=1):
    print(i, x)

Python: n = int(input())

class Node:
    def __init__(self, idd, neighbors):
        self.idd = idd
        self.neighbors = neighbors
        self.dist = -1
        
    def __repr__(self):
        return "{0} {1}".format(self.idd, self.dist)
    
def breadthFirstSearch(Nodes):
    stack = [Nodes[0]]
    Nodes[0].dist = 0
    while len(stack) > 0:
        current = stack.pop(0)
        for v in current.neighbors:
            v_node = Nodes[v-1]
#             print('current:{}, v_node:{}'.format(current, v_node))
            if(v_node.dist == -1):
                v_node.dist = current.dist + 1
                stack.append(v_node)
            else:
                v_node.dist = v_node.dist if v_node.dist < current.dist + 1 else current.dist + 1
    return Nodes

Nodes = [None] * n
for i in range(n):
    row = [int(tt) for tt in input().split()]
    Nodes[row[0]-1] = Node(row[0], [ row[j + 2] for j in range(row[1])])

Nodes = breadthFirstSearch(Nodes)
for node in Nodes:
    print(node)

Python: from collections import deque


def get_next_node(node, discovery_time, adj_mat):
    for i, node in enumerate(adj_mat[node]):
        if discovery_time[i] == 0 and node == 1:
            return i
    return None

def bfs(node, adj_mat):
    distances = [-1] * len(adj_mat)

    distances[node] = 0
    q = deque(maxlen=len(adj_mat))
    q.append(0)
    while q:
        visit_node = q.popleft()
        for j in range(len(adj_mat)):
            if adj_mat[visit_node][j] and distances[j]==-1:
                distances[j] = distances[visit_node] + 1
                q.append(j)
    
    for i, d in enumerate(distances):
        print(i+1, d)


if __name__ == "__main__":
    n_node = int(input())
    # f = open('alds1_11_c-input.txt', 'r')
    # n_node = int(f.readline())

    adjacency_mat = [[0 for i in range(n_node)] for j in range(n_node)]
    for i in range(n_node):
        command = list(map(int, input().split()))
        # command = list(map(int, f.readline().split()))

        i = command.pop(0) - 1
        n_edge = command.pop(0)

        for j in command:
            adjacency_mat[i][j-1] = 1

    # f.close()
    discovery_time = [0] * n_node
    finish_time = [0] * n_node
    bfs(0, adjacency_mat)

Python: import collections

N = int(input())
route = []
for i in range(N):
    a = list(map(int, input().split()))
    route.append(a[2:])
ans = [-1 for _ in range(N)]
ans[0] = 0
check = collections.deque([0])#now distance
while check:
    now = check.popleft()
    for next in route[now]:
        next -= 1
        if ans[next] == -1:
            check.append(next)
            ans[next] = ans[now]+1
for i in range(N):
    print(i+1, ans[i])

Python: N= int(input())
E = [input().split()[2:] for _ in range(N)]
Q = [0]
L = [0] + [-1]*N
flag = [1] + [0]*N
def func(ide):
    global Q
    for i in E[ide]:
        i = int(i) - 1
        if frag[i] != 1:frag[i] = 1;L[i] = L[ide] +1 ;Q.append(i)
    

while Q:top = Q.pop(0);func(top)

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

Python: from collections import deque
from enum import Enum

class Color(Enum):
  WHITE = 0
  GRAY = 1
  BLACK = 2


N = int(input())
adj = [list(map(int, input().split()))[2:] for i in range(N)]


colors = [Color.WHITE for i in range(N)]
INF = N
d = [-1 for i in range(N)]
d[0] = 0

q = deque()
q.append(1)
colors[0] == Color.GRAY
while len(q) > 0:
  u = q.popleft()-1
  for v in adj[u]:
    v -= 1
    if colors[v] != Color.WHITE:
      continue
    d[v] = d[u] + 1
    colors[v] = Color.GRAY
    q.append(v+1)
  colors[u] = Color.BLACK

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

Python: N= int(input())
frag, T, L,Q = [0]*N, [0]*N, [0]*N, [0]
a,frag[0] = 100, 1
def func(ide):
    for i in E[ide]:
        i = int(i) - 1
        if frag[i] != 1:frag[i] = 1;L[i] = L[ide] +1 ;Q.append(i) 
        else:return
E = [input().split()[2:] for _ in range(N)]

while Q:top = Q[0];func(top);del Q[0]
    
for i in range(N):print(i + 1 ,int(L[i]))

Python: m = [[0 for _ in range(n+1)] for _ in range(n+1)]
mm = [[] for _ in range(n+1)]

n = int(input())
for _ in range(n):
	tmp = [int(x) for x in input().split()]
	u,k,l = tmp[0],tmp[1],tmp[2:]
	mm[u] += tmp[2:]
	for x in l:
		m[u][x] = 1
		
dp = [float('inf') for _ in range(n+1)]
queue = [1]

while queue:
	t = queue.pop(0)
	for x in mm[t]:
		if dp[x] > dp[t] + 1:
			dp[x] = dp[t] + 1
			queue.append(x)
		else:
			pass
			
for i,x in enumerate(queue):
	if i == 0:
		pass
	else:
		if x == float('inf'):
			print(i, -1)
		else:
			print(i, x)

Python: n = int(input())
graph = [[0 for i in range(n)] for j in range(n)]
d = [0] * n
f = [0] * n
queue = [0]


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

f[0] = 1
while len(queue) != 0:
    i = queue.pop(0)
    for j in range(n):
        if (graph[i][j] == 1) & (f[j] == 0):
            queue.append(j)
            f[j] = 1
            d[j] = d[i] + 1

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

Python: # -*- coding: utf-8 -*-
'''
所要時間は、分位であった。
'''


# ライブラリのインポート
#import re #正規表現
import sys
#import heapq
#import bisect
from collections import deque
#import math

def main():
    inf = 10000
    n = int(input())
    D = [inf for i in range(n)]
    L = [[] for i in range(n)]
    for i, line in enumerate(sys.stdin):
        L[i] = list(map(lambda x: int(x)-1, list(line.strip("\n").split())))

    q = deque([0])
    D[0] = 0
    while(len(q)):
        u = q.popleft()
        if L[u][1] == -1:
            continue
        for j in range(2,len(L[u])):
            if D[L[u][j]] == inf:
                q.append(L[u][j])
            D[L[u][j]] = min(D[L[u][0]] + 1, D[L[u][j]]) 

                      
    for i in range(n):
        print("{} {}".format(i+1,D[i])) if D[i] < inf else print("{} {}".format(i+1,-1))
            
if __name__ == '__main__':
    main()