Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

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

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

Python: # -*- coding: utf-8 -*-
"""
Created on Sun Jul  8 10:56:33 2018

@author: maezawa
"""
n = int(input())
adj = [[] for _ in range(n)]
d = [-1 for _ in range(n)]
d[0] = 0


for j in range(n):
    ain = list(map(int, input().split()))
    u = ain[0]
    k = ain[1]
    for i in range(k):
        adj[u-1].append(ain[i+2]-1)
    adj[u-1].sort()
    #print(*adj[u-1])

stack = [0]

while stack:
    print(stack)
    current = stack[-1]
    flag = 0
    for k in adj[current]:
        if d[k] <= 0:
            d[k] = d[current]+1
            stack.append(k)
            flag = 1
    if flag == 0:
        stack.pop()

    #print('current = {}, t = {}'.format(current, t))
    #print('stack', *stack)

for i in range(n):
    print('{} {}'.format(i+1, d[i]))

Python: from collections import deque
n = int(input())
u = []
k = []
v = []

for i in range(n):
    tmp = list(map(int, input().split()))
    u.append(tmp[0])
    k.append(tmp[1])
    if tmp[1] != 0:
        v.append(tmp[2:])
    else:
        v.append([])
        
d = deque([1])
dis = [-1]*n
dis[0] = 0
visit = [False]*n
visit[0] = True
while len(d) > 0:
    go = d[0]
    flag = False
    for i in v[go-1]:
        if not visit[i-1]:
            d.append(i)
            dis[i-1] = dis[go-1] + 1
            visit[i-1] = True
            flag = True
    d.popleft()
    
for i in range(n):
    print(i+1, dis[i])

Python: from collections import deque

n = int(input())
m = [[0 for j in range(n)] for i in range(n)]
color = [0 for i in range(n)]
q = deque()
dist = [-1 for i in range(n)]


def bfs(s):
    color[s], dist[s] = 1, 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], dist[v] = 1, dist[u] + 1
                q.append(v)

        color[u] = 2


def main():
    for i in range(n):
        data = list(map(int, input().split()))
        for j in range(2, len(data)):
            m[data[0]-1][data[j]-1] = 1

    for i in range(n):
        if color[i] == 0:
            bfs(i)

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


if __name__ == '__main__':
    main()

Python: import sys
input = sys.stdin.readline

from collections import deque

def getNeighbor(A, i):
    a = len(A)
    for k in range(2, a):
        M[i][A[k]-1] = 1

def bfs():
    u = q.popleft()
    c[u] = 1

    for v in range(n):
        if M[u][v] and c[v] == 0:
            q.append(v)
            d[v] = d[u] + 1
            c[v] = 1

    if q:
        bfs()

    return

    bfs()

q = deque([0])

n = int(input())
#color
c = [0] * n
d = [0] + [-1] * (n-1) #depth

M = [[0] * n for _ in range(n)]
t = 0

for i in range(n):
    A = list(map(int, input().split()))
    getNeighbor(A,i)

bfs()

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

Python: def get_depth(graph,tmp_depth,vertex_list,depth_list):
    new_vertex_list=[]
    for vertex in vertex_list:
        for j in range(len(depth_list)):
            if(graph[vertex][j]!=0 and depth_list[j]==-1):
                depth_list[j]=tmp_depth + 1
                new_vertex_list.append(j)
    get_depth(graph,tmp_depth+1,new_vertex_list,depth_list)


#グラフの作成
n=int(input())
graph=[[0]*n for loop in range(n)]
for loop in range(n):
    tmp_ope=list(map(int,input().split()))
    for j in range(tmp_ope[1]):
        graph[tmp_ope[0]-1][tmp_ope[j+2]-1]=1


depth_list=[-1]*n
depth_list[0]=0
vertex_list=[0]
get_depth(graph,0,vertex_list,depth_list)

for i in range(n):
    print(f"{i+1} {depth_list[i]}")

Python: # -*- coding: utf-8 -*-
import sys
from collections import deque
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
input=lambda: sys.stdin.readline().rstrip()
YesNo=lambda b: print('Yes' if b else 'No')
YESNO=lambda b: print('YES' if b else 'NO')

def main():
    N=int(input())
    edge=[[] for _ in range(N)]
    for i in range(N):
        l=list(map(lambda x:int(x)-1,input().split()))
        edge[i]=l[2:]
    d=[INF]*N
    d[0]=0
    que=deque()
    que.append(0)
    while que:
        v=que.popleft()
        for nv in edge[v]:
            if d[nv]>d[v]+1:
                d[nv]=d[v]+1
                que.append(nv)
    for i in range(N):
        print(i+1,d[i] if d[i]!=INF else -1)

if __name__ == '__main__':
    main()

Python: def bfs(adj, s):
    n = len(adj)
    d = [-1 for _ in range(n)]
    c = [0 for _ in range(n)]

    d[s] = 0
    c[s] = 1

    queue = [s]

    while len(queue) > 0:
        u = queue.pop()
        for v in adj[u]:
            if c[v] == 0:
                c[v] = 1
                d[v] = d[u] + 1
                queue.append(v)

    return d


n = int(input())
adj = [[] for _ in range(n)]
for _ in range(n):
    s = [int(x) for x in input().split()]
    u = s[0]
    for v in s[2:]:
        adj[u - 1].append(v - 1)

d = bfs(adj, 0)

for i in range(n):
    print(str(i + 1) + " " + str(d[i]))

Python: N= int(input())
E = [input().split()[2:] for _ in range(N)]
Q = [0]
L = [0] + [-1]*N
frag = [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[0];func(top);del Q[0]

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