Go: package main

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

func main() {
	scn := bufio.NewScanner(os.Stdin)
	scn.Split(bufio.ScanWords)
	nextInt := func() int { scn.Scan(); r, _ := strconv.Atoi(scn.Text()); return r }
	w := bufio.NewWriter(os.Stdout)

	n := nextInt()
	vecs := make([][]int, n)
	for i := 0; i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			vecs[u-1] = append(vecs[u-1], nextInt()-1)
		}
	}

	ds := make([]int, 0, n)
	for i := 0; i < n; i++ {
		ds = append(ds, -1)
	}

	q := make([]int, 0, n)
	q = append(q, 0)
	ds[0] = 0

	for len(q) > 0 {
		i := pop(&q)
		for _, v := range vecs[i] {
			if ds[v] == -1 {
				ds[v] = ds[i]+1
				q = append(q, v)
			}
		}
	}

	for i, d := range ds {
		fmt.Fprintln(w, i+1, d)
	}

	w.Flush()
}

func pop(q *[]int) int {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

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

using namespace std;

int main(){
	int n, u, k, v;
	int D[100];
	bool adj[100][100] = {};
	cin >> n;
	for (int i = 0; i < n; i++){
		cin >> u >> k;
		for (int j = 0; j < k; j++){
			cin >> v;
			adj[u-1][v-1] = true;
		}
	}
	for (int i = 0; i < n; i++){
		D[i] = -1;
	}
	queue<int> Q;
	Q.push(1);
	D[0] = 0;
	e[0] = 1;
	while(!Q.empty()){
		int m = Q.front();
		Q.pop();
		for (int i = 0; i < n; i++){
			if (adj[m-1][i] == 1 && e[i] == 0){
				D[i] = D[m-1]+1;
				Q.push(i);
				e[i] = 1;
			}
		}
	}
	
	for (int i = 0; i < n; i++){
		cout << i+1 << ' ' << D[i] << endl;
	}
}

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


using namespace std;


static const  int N =  100;
static const  int no =  -2;

int graph[N][N] = {{}};
int d[N] = {};
int n;

void bfs(int v){
  queue<int> Q; 
  Q.push(v);

  int 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) continue;
      if(d[i] != no) continue;
      d[i] = d[u] +1;
      Q.push(i);
    }
  }
}


int main(){
  int u,v,k;
  //graph
  cin >> n ;

  for(int i = 0; i < n; i++){
    cin >> u >> k ;
    for(int j = 0; j < k ; j++){
      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;

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() {

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

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

  bfs(0);

  return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

typedef long long ll;

const int INF = 1e9;

int main()
{
  int n = 0;
  fscanf(stdin, "%d", &n);
  vector<vector<int> > mat(n + 5, vector<int>(n + 5, 0));
  for (int i = 0; i < n; ++i) {
    int v = -1, k = -1, u = -1;
    fscanf(stdin, "%d %d", &v, &k);
    for (int j = 0; j < k; ++j) {
      fscanf(stdin, "%d", &u);
      mat[v][u] = 1;
    }
  }
  vector<int> visited(n + 5, 0), cost(n + 5, INF);
  queue<int> que;
  cost[1] = 0;
  que.push(1);
  while (!que.empty()) {
    int v = que.front(); que.pop();
    if (visited[v]) { continue; }
    visited[v] = 1;
    for (int u = 1; u <= n; ++u) {
      if (mat[v][u] && !visited[u]) {
        cost[u] = min(cost[u], cost[v] + 1);
        que.push(u);
      }
    }
  }
  for (int i = 1; i <= n; ++i) {
    fprintf(stdout, "%d %d\n", i, visited[i] ? cost[i] : -1);
  }
  return 0;
}

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

using namespace std;
#define MAX 100

const int INF = (1<<21);
int mat[MAX][MAX] = {};
int n, d[MAX] = {};
bool c[MAX];

void bfs(int u){
    queue<int> p; 
    int now = 0;
    d[u] = now++;
    c[u] = true;

    p.push(u);
    while(!p.empty()){
        int x = p.front(); p.pop();
        for(int i = 0; i < n; i++){
            if(mat[x][i] && !c[i]){
                p.push(i);
                c[i] = true;
                d[i] = d[x]+1;
            }
        }
    }
}

int main(){
    cin >> n;
    
    for(int i = 0; i < n; i++){
        int x, k, y;
        cin >> x >> k;
        while(k-- > 0){
            cin >> y;
            mat[x-1][y-1] = 1;
        }
    }

    memset(d, INF, MAX);
    bfs(0);

    for(int i = 0; i < n; i++){
        cout << (i+1) << " " << d[i] << endl;
    }
    return 0;
}

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

using namespace std;
static const int N=100;
static const int INF=(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]=INF;
  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]!=INF)continue;
      d[v]=d[u]+1;
      q.push(v);
    }
  }

  for(int i=0;i<n;i++){
    cout<<i+1<<" "<<((d[i]==INF)? (-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 <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 <queue>
#include <vector>

#define MAX_NODE 100
#define INF 1000000000

using namespace std;

int d[MAX_NODE];
vector<int> adj[MAX_NODE];

void bfs(int n, int start) {
	queue<int> que;

	for (int i = 0; i < n; i++)
		d[i] = (i == start ? 0 : INF);

	que.push(start);
	while(!que.empty()) {
		int from = que.front();
		que.pop();

		for (int i = 0; i < adj[from].size(); i++) {
			int to = adj[from][i];
			if (d[to] == INF) {
				d[to] = d[from] + 1;
				que.push(to);
			}
		}
	}
}

int main() {
	int n;

	cin >> n;

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		u--;
		while (k--) {
			int v;
			cin >> v;
			v--;
			adj[u].push_back(v);
		}
	}

	bfs(n, 0);

	for (int i = 0; i < n; i++)
		cout << i + 1 << " " << d[i] << endl;

	return 0;
}