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<cstdio>
#include<queue>
#include<iostream>
using namespace std;
int n, visited[101], d[101];
int adj[101][101];
queue<int> q;
void bfs(int u)
{
  if(visited[u]) return;
  q.push(u);
  visited[u] = 1;
  while(!q.empty())
  {
    int v = q.front();
    for(int i=1; i<=n; i++)
    {
      if(adj[v][i] && visited[i]==0)
      {
        q.push(i);
        visited[i] = 1;
        d[i] = d[v] + 1;
      }
    }
    q.pop();
  }
}
int main()
{
  scanf("%d", &n);
  for(int i=0; i<=n; i++)
  {
    for(int j=0; j<=n; j++)
      adj[i][j] = 0;
    visited[i] = 0;
    d[i] = -1;
  }
  d[1] = 0;
  int u, k, v;
  for(int i=0; i<n; i++)
  {
    scanf("%d%d", &u, &k);
    for(int j=0; j<k; j++)
    {
      scanf("%d", &v);
      adj[u][v] = 1;
    }
  }
//  for(int i=1; i<=n; i++)
//  {
//    if(visited[i] == 0)
//      bfs(i);
//  }
  bfs(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;

typedef long long ll;
typedef pair<ll, ll> P;

#define pb push_back
#define rep(i, n) for(int i = 0; i < (n); i++)
#define FOR(i, a, n) for(int i = a; i < (n); i++)
#define mod (ll)(1e9+7)
#define int ll

static const int N = 100;
static const int no = -1;

__attribute__((constructor))
void initial() {
  cin.tie(0);
  ios::sync_with_stdio(false);
}

ll graph[N][N] = {0}, d[N] = {0}, n;

void bfs(int v) {
  queue<int> q;
  q.push(v);
  ll u;
  for(int i = 1; i <= n; i++) d[i] = no;
  d[v] = 0;
  while(!q.empty()) {
    u = q.front(); q.pop();
    for(int i = 1; i <= n; i++) {
      if((graph[u][i] == 0) || (d[i] != no)) continue;
      d[i] = d[u] + 1;
      q.push(i);
    }
  }
}

signed main() {
	ll u, v, k;
  cin >> n;
  rep(i, n) {
    cin >> u >> k;
    rep(j, k) {
      cin >> v;
      graph[u][v] = 1;
    }
  }

  bfs(1);

  for(int i = 1; i <= n; i++) {
    cout << i << " " << d[i] << endl;
  }

	return 0;
}

C++: #include<iostream>
#include<queue>
using namespace std;

int A[101][101] = {0};
int n, tt = 0, d[101] = {0}, color[101] = {0};
queue<int> Q;


void bfs (int u) {
    int i, j ,k;
    Q.push(u);
    d[u] = tt++;
    color[u] = 1;
    while ( !Q.empty() ) {
        j = Q.front();
        Q.pop();
        for ( i = 1; i <= n; i++ ) {
            if ( A[j][i] == 1 && color[i] != 1 ) {
                Q.push(i);
                color[i] = 1;
                d[i] = d[j] + 1;
            }

        }
        }
    }



int main() {
    int i, j, k, v;
    cin >> n;
    for ( i = 0; i < n; i++ ) {
        cin >> j >> k;
        while ( k-- ) {
            cin >> v;
            A[j][v] = 1;
        }
    }

    bfs(1);
    for ( i = 1; i <= n; i++ ) if ( color[i] != 1 ) d[i] = -1;
    for ( i = 1; i <= n; i++ ) cout << i << ' ' << d[i] << endl;

    return 0;

}

C++: #include<iostream>
#include<queue>
using namespace std;
int N;
int D[101];
void bfs(int src){
    int u[101],k[101],a[10010],d[101][101];
    bool visit[101];
    for(int i=1;i<=N;++i){
        cin>>u[i]>>k[i];
        for(int j=0;j<k[i];++j){
            cin>>a[j];
            d[u[i]][a[j]]=1;
        }
        visit[i]=true;
    }
    queue<int>Q;
    Q.push(src);
    D[src]=0;
    visit[src]=false;
    while(!Q.empty()){
        int cur=Q.front();
        Q.pop();
        for(int i=1;i<=N;++i){
            if(d[cur][i]==1&&visit[i]){
                visit[cur]=false;
                visit[i]=false;
                D[i]=D[cur]+1;
                Q.push(i);
            }
        }
    }
    for(int i=1;i<=N;++i){
        if(i!=1&&D[i]==0){
            D[i]=-1;
        }
        cout<<i<<" "<<D[i]<<endl;
    }
}
int main(){
    cin>>N;
    int start=1;
    bfs(start);
}

C++: #include <iostream>
#include <queue>
#include <algorithm>
using namespace std;

int M[101][101], cond[101], d[101], n;

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

void bfs(int x)
{
	queue<int> Q;

	Q.push(x);
	cond[x] = -1;
	d[x] = 0;

	while (!Q.empty()) {
		int u = Q.front();
		for (int i = 1; i <= n; i++) {
			if (M[u][i] == 1 && cond[i] == 0) {
				Q.push(i);
				d[i] = d[u] + 1;				
				cond[i] = -1;
			}
		}
		Q.pop();
		cond[u] = 1;
	}
}

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);

	cin >> n;
	setAdj();

	for (int i = 1; i <= n; i++)
		if (cond[i] == 0) bfs(i);

	for (int i = 1; i <= n; i++)
		cout << i << " " << d[i] << endl;

	return 0;
}

C++: #include<iostream>
#include<queue>

using namespace std;
static const int N=100;
static const int INFTY = (1<<21);

int n,Mtw[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 utw;
    while(!q.empty()){
        utw=q.front(); q.pop();
        for(int v=0;v<n;v++){
            if(Mtw[utw][v]==0)continue;
            if(d[v]!=INFTY)continue;
            d[v]=d[utw]+1;
            q.push(v);
        }
    }
    for(int i=0;i<n;i++){
        cout<<i+1<<" "<<((d[i]==INFTY)?(-1):d[i])<<endl;
    }
}

int main(){
    int utw,ktw,vtw;

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

    for(int i=0;i<n;i++){
        cin>>utw>>ktw;
        utw--;
        for(int j=0;j<ktw;j++){
            cin >> vtw;
            vtw--;
            Mtw[utw][vtw]=1;
        }
    }

    bfs(0);

    return 0;
}

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[u] != 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;
}