Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

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

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

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;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <queue>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define  all(x) (x).begin(),(x).end()
typedef long long ll;

vector<int> g[105];
vector<int> d(105, -1);

int main(){
    int n;
    cin >> n;
    rep(i,n){
        int u, k, v;
        cin >> u >> k;
        rep(j, k){
            cin >> v;
            g[u].push_back(v);
        }
    }
    queue<int> q;
    q.push(1);
    d[1] = 0;
    while(!q.empty()){
        int x = q.front(); 
        q.pop();
        for(int v : g[x]){
            if (d[v] != -1) continue;
            q.push(v);
            d[v] = d[x]+1;
        }
    }
    for(int i = 1; i <= n; i++){
        printf("%d %d\n", i, d[i]);
    }
    return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int G[223][223];
int dis[223];
int n;

struct st {
  int pos;
  int v;
};

int main() {
  cin >> n;
  for(int i = 1; i <= n; i++) {
    int u, v;
    scanf("%d%d", &u, &v);
    for(int j = 0; j < v; j++) {
      int t;
      scanf("%d", &t);
      G[u][t] = G[t][u] = 1;
    }
  }

  memset(dis, 0x3f, sizeof dis);

  int start = 1;
  queue<st> q;
  q.push((st) {
    1, 0
  });

  while(!q.empty()) {

    st u = q.front();
    q.pop();
    if(dis[u.pos] < 1000000) continue;

    dis[u.pos] = u.v;

    for(int i = 1; i <= n; i++) {
      if(i == u.pos) continue;
      if(G[i][u.pos] == 0) continue;
      q.push((st){i, u.v + 1});
    }
  }

  for(int i=1;i<=n;i++) {
    printf("%d %d\n", i, dis[i] > 100000 ? -1 : dis[i]);
  }

  return 0;
}