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()
}

C++: #include <iostream>
#include <queue>
#include <vector>
#define pb push_back
using namespace std;
queue<int> q;
vector<int> v[110];
bool seen[110] = {0};
int main() {
    int n; cin >> n;
    for (int i = 0; i < n; i++) {
        int u, k; cin >> u >> k;
        while (k--) {
            int tmp; cin >> tmp;
            v[u].pb(tmp);
        }
    }
    q.push(1);
    int d[n + 1];
	for (int i = 0; i <= n; i++)
		d[i] = -1;
    d[1] = 0; seen[1] = 1;
    while (!q.empty()) {
        for (int x: v[q.front()]) {
            if (!seen[x]) {
                q.push(x);
                seen[x] = 1;
                d[x] = d[q.front()] + 1;
            }
        }
        q.pop();
    }
    for (int i = 1; i <= n; i++)
        cout << i << ' ' << d[i] << '\n';
    return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;

constexpr int LEN = 105;
bool ga[LEN][LEN];

void bfs(int d[], const int n){
	queue<int> q;
	q.push(0);
	d[0] = 0;
	while(q.size()){
		int id = q.front(); q.pop();
		rep(i, n){
			if(ga[id][i] && d[i] < 0){
				d[i] = d[id] + 1;
				q.push(i);
			}
		}
	}
	return;
}

int main(){
	int d[LEN];
	memset(d, -1, LEN*sizeof(int));
	memset(ga, 0, LEN*LEN*sizeof(bool));
	int n; cin >> n;
	rep(i, n){
		int u, k; cin >> u >> k;
		rep(j, k){
			int v; cin >> v;
			ga[u-1][v-1] = 1;
		}
	}

	bfs(d, n);
	rep(i, n) cout << i+1 << ' ' << d[i] << endl;

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, start, end) for (long long i = start; i < end; ++i)
#define all(x) (x).begin(), (x).end()
#define len(x) ((long long)(x).size())
#define srt(x) sort((x).begin(), (x).end())
#define rsrt(x) sort((x).rbegin(), (x).rend())
#define g(a, b) __gcd((a), (b))
#define l(a, b) ((a) / __gcd((a), (b)) * (b))
using namespace std;
using ll = long long;
using ld = long double;
using vll = vector<long long>;
using vllvll = vector<vll>;
using vc = vector<char>;
using vs = vector<string>;
using um = unordered_map<long long, long long>;
template<class T>void print(T x) { cout << '\n' << "== " << x << " ==" << '\n'; }
template<class T>void print1d(T x,ll n=-1){if(n==-1)n=x.size();rep(i,0,n){cout<<x[i]<<' ';}cout<<'\n';}
template<class T>void print2d(T x,ll r=-1,ll c=-1){if(r==-1)r=x.size();if(c==-1)c=x[0].size();rep(i,0,r)print1d(x[i],c);}
template<class T>void precise(T x) { cout << setprecision(21) << x << '\n'; }
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
template<class T, class U>T rem(T a, U b) { return a - b*floor(a/b); }
template<class T>ld deg2rad(T deg) { return M_PI * deg / 180.0; }
template<class T>ld rad2deg(T rad) { return 180.0 * rad / M_PI; }
const long double pi = M_PI;
const long double doublepi = M_PI * 2.0;
const long double halfpi = M_PI / 2.0;
const long long big = 1LL << 50;
const long long inf = 1LL << 60;
const long long MOD = 1e9 + 7;

const long long MAX = 10000; // SET
vllvll Mat(MAX, vll(0));
vll dist(MAX);

template<class T>
void bfs(T start)
{
    fill(dist.begin(), dist.end(), inf);
    dist[start] = 0;

    queue<T> q;
    q.push(start);

    while (! q.empty()) {
        auto now = q.front(); q.pop();
        for (auto adj : Mat[now]) {
            if (dist[adj] == inf) {
                dist[adj] = dist[now] + 1;
                q.push(adj);
            }
        }
    }
}

int main()
{
    // INIT Mat
    ll n;
    cin >> n;
    ll u, k, v;
    rep(i, 0, n) {
        cin >> u >> k;
        --u;
        rep(j, 0, k) {
            cin >> v;
            --v;
            Mat[u].push_back(v);
        }
    }

    ll start = 0;

    bfs(start);
    rep(i, 0, n) {
        if (dist[i] > big) 
            cout << i+1 << ' ' << -1 << endl;
        else
            cout << i+1 << ' ' << dist[i] << endl;
    }
}

C++: #include<iostream>
#include<queue>
using namespace std;
static const int N = 100;
static const int INFTY = (1 << 21);

int n, M[N][N];
int d[N];

void bfs(int s)
{
    queue<int> q;
    q.push(s);
    for (int i = 0; i < n; i++) d[i] = INFTY;
    d[s] = 0;
    int u;
    while (!q.empty())
    {
        u = q.front();
        q.pop();
        for (int v = 0; v < n; v++)
        {
            if (M[u][v] == 0) continue;
            if (d[v] != INFTY) continue;
            d[v] = d[u] + 1;
            q.push(v);
        }
    }
    for (int i = 0; i < n; i++)
    {
        cout << i + 1 << " " << ( (d[i] == INFTY) ? (-1) : d[i]) << endl;
    }
}

int main()
{
    int u, k, v;

    cin >> n;
    for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            M[i][j] = 0;
        }
    }

    for (int i = 0; i < n; i++)
    {
        cin >> u >> k;
        u--;
        for (int j = 0; j < k; j++)
        {
            cin >> v;
            v--;
            M[u][v] = 1;
        }
    }

    bfs(0);
    
    return 0;
}