Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Queue struct {
	arr []int
}

func (q *Queue) push(v int) {
	q.arr = append(q.arr, v)
}

func (q *Queue) pop() int {
	res := q.arr[0]
	q.arr = q.arr[1:]
	return res
}

func (q *Queue) isEmpty() bool {
	return len(q.arr) == 0
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	var q Queue
	seen := make([]int, N)
	for i := 0; i < N; i++ {
		seen[i] = -1
	}
	var search func(cur int)
	search = func(cur int) {
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if seen[next] == -1 {
				q.push(next)
				seen[next] = seen[cur] + 1
			}
		}
	}
	q.push(0)
	seen[0] = 0
	for !q.isEmpty() {
		search(q.pop())
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i+1, seen[i])
	}
	wtr.Flush()
}

Python: # 28
# ALDS_11_C - 幅優先探索

from collections import deque

n = int(input())
u_l = []
k_l = []
v_l = []

for i in range(n):
    _v_l = []
    for j, _ in enumerate(input().split()):
        if j == 0:
            u_l.append(int(_))
        elif j == 1:
            k_l.append(int(_))
        else:
            _v_l.append(int(_))
    v_l.append(_v_l)
        
d_l = [-1]*n
d_l[0] = 0
s_dq = deque([1])
while len(s_dq) > 0:
    _s = s_dq.popleft()
    _s -= 1
    for i in range(k_l[_s]):
        _v = v_l[_s][i]
        if d_l[_v-1] == -1:
            s_dq.append(_v)
            d_l[_v-1] = d_l[_s] + 1

for _id, _d in zip(range(1,n+1), d_l):
    print(_id, _d)

Python: from collections import deque
def bfs(g,v):
    q=deque([v]) ; vis=[0]*n
    vis[v]=1 ; stg[v]=0
    while q:
        v=q[0]
        for p in g[v]:
            if vis[p]==0: 
                q.append(p)
                vis[p]=1
                stg[p]=stg[v]+1
        q.popleft()
n=int(input())
g=[[] for i in range(n)]
for _ in range(n):
    a=[int(i)-1 for i in input().split()]
    for i in a[2:]: g[a[0]].append(i)
stg=[-1]*n
bfs(g,0)
for i in range(n):
    print(i+1,stg[i])

Python: from collections import deque

def main():

    inf = 1000000007
    n = int(input())
    e = [[] for _ in range(n)]
    d = [inf]*n

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

    d[0] = 0
    dq = deque([])
    dq.append([0,0])
    while dq:
        c,v = dq.popleft()
        for u in e[v]:
            if d[u]==inf:
                d[u] = c+1
                dq.append([c+1,u])

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

if __name__ == '__main__':
    main()

Python: n=int(input())
ps=[0 for j in range(n+1)]

for i in range(n):
    p,d,*vs=[int(j) for j in input().split()]
    ps[p]=vs
    
dist=[-1 for i in range(n+1)]    
    
d=0
queue=[1]

while queue:
    pos=queue.pop(0)
    if dist[pos] == -1:
        dist[pos]=d
    for i in ps[pos]:
        if dist[i]==-1:
            queue.append(i)
            dist[i]=dist[pos]+1

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

Python: from collections import deque

n = int(input())
u = [[] for i in range(n+1)] #隣接リスト
for i in range(n):
    v = list(map(int, input().split()))
    u[v[0]] = v[1:] #v = [次数, 頂点...]

d = [-1] * (n+1)
visited = [False] * (n+1)

d[1] = 0
visited[1] = True
que = deque([1])
while len(que) > 0:
    c = que.popleft()
    for i in range(1, u[c][0]+1):
        if not visited[u[c][i]]:
            que.append(u[c][i])
            visited[u[c][i]] = True
            d[u[c][i]] = d[c] + 1

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

Python: from collections import deque

n = int(input())
graph_W = []
for _ in range(n):
    graph_W.append(list(map(int, input().split())))
    
num_root = [0]*n
work_queue = deque([])
visited = set()

work_queue.append(1)
visited.add(1)
cnt = 0
while work_queue:
    here = work_queue.popleft() - 1
    num_node = graph_W[here][1]
    cnt += 1
    if num_node == 0:
        continue
    for k in range(num_node):
        num_graph = graph_W[here][k+2]
        if num_graph not in visited:
            work_queue.append(num_graph)
            visited.add(num_graph)
            num_root[num_graph-1] = num_root[here] + 1


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

Python: from collections import deque

INF = 1e9

def BFS(n, adj):
    d = [INF] * N
    d[0] = 0
    next_v = deque([0]) # ?¬??????????????????????
    
    while next_v:
        u = next_v.popleft()
        
        for v in adj[u]:
            if d[v] == INF:
                d[v] = d[u] + 1
                next_v.append(v)
    
    return d

N = int(input())
Adj = [None] * N

for i in range(N):
    u, k, *vertex = [int(i)-1 for i in input().split()]
    Adj[u] = vertex

distance = BFS(N, Adj)

for i, di in enumerate(distance, start = 1):
    if di == INF:
        print(i, -1)
    else:
        print(i, di)

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


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

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

Python: 
def BFS(s = 0):
    Q.pop(0)
    color[s] = 2
    for j in range(len(color)):
        if A[s][j] == 1 and color[j] == 0:
            Q.append(j)
            color[j] = 1
            d[j] = d[s] + 1
    if len(Q) != 0:
        BFS(Q[0])

n = int(raw_input())
A = [0] * n
for i in range(n):
    A[i] = [0] * n

for i in range(n):
    value = map(int, raw_input().split())
    u = value[0] - 1
    k = value[1]
    nodes = value[2:]
    for j in range(k):
        v = nodes[j] - 1
        A[u][v] = 1

color = [0] * n
Q = [0]
d = [-1] * n
d[0] = 0

BFS(0)

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