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 collections import deque

def bfs(adj_mat, d):
    Q = deque()
    N = len(d)
    color = ["W" for n in range(N)]

    Q.append(0)
    d[0] = 0

    while len(Q) != 0:
        u = Q.popleft()

        for i in range(N):
            if adj_mat[u][i] == 1 and color[i] == "W":
                color[i] = "G"
                d[i] = d[u] + 1
                Q.append(i)

        color[u] = "B"

    for i in range(N):
        if color[i] != "B":
            d[i] = -1

def Main():
    N = int(input())

    adj_mat = [[0 for n in range(N)] for n in range(N)]
    d = [0] * N

    for n in range(N):
        u, k , *V = map(int, input().split())

        if k > 0:
            for i in V:
                adj_mat[n][i - 1] = 1

    bfs(adj_mat, d)

    for n in range(N):
        print("{} {}".format(n + 1, d[n]))
Main()

Python: if __name__ == '__main__':
    from sys import stdin
    input = stdin.readline

    from collections import deque, defaultdict
    from copy import deepcopy

    INFTY = -1   # 探索しなかったやつを-1としてprintしやすくするために-1とした。

    n = int(input())

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

    def bfs(s):
        q = deque()
        q.append(s)
        d = [INFTY]*n
        d[s] = 0
        while q: # qが空だとwhileループから抜ける
            u = q.popleft()  # pythonのdequeはpopleft関数で戻り値がpopした要素になる
            for v in range(n):
                if M[u][v] == 0:
                    continue
                if d[v] != INFTY:
                    continue
                d[v] = d[u] + 1
                q.append(v)
        for i in range(n):
            print(str(i+1) + ' ' + str(d[i]))

    for _ in range(n):
        u, k, *vv = map(int, input().split())
        u -= 1
        for v in vv:
            v -= 1
            M[u][v] = 1

    bfs(0)

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 _ in range(n)]
bfs()