Go: package main

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

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Scan()
	num, _ := strconv.Atoi(sc.Text())
	nodes := make(map[int]*node)

	for i := 0; i < num; i++ {
		sc.Scan()
		id, _ := strconv.Atoi(sc.Text())
		sc.Scan()
		nodeNum, _ := strconv.Atoi(sc.Text())
		n := node{id, make([]int, 0), -1}
		for j := 0; j < nodeNum; j++ {
			sc.Scan()
			nid, _ := strconv.Atoi(sc.Text())
			n.nexts = append(n.nexts, nid)
		}
		nodes[id] = &n
	}
	nodes[1].depth = 0

	walk(1, 0, &nodes)
	for i := 1; i < len(nodes)+1; i++ {
		fmt.Printf("%v %v\n", (*nodes[i]).id, (*nodes[i]).depth)
	}
}

var time int
var record [100][100]bool
var q Queue

func walk(nid int, from int, nodes *map[int]*node) {
	q.Enqueue((*nodes)[nid])
	for !q.IsEmpty() {
		n := q.Dequeue().(*node)
		for _, v := range n.nexts {
			n2 := (*nodes)[v]
			if n2.depth != -1 {
				continue
			}
			n2.depth = n.depth + 1
			q.Enqueue((*nodes)[v])
		}
	}
}

type node struct {
	id    int
	nexts []int
	depth int
}

// Queue is Queue
type Queue struct {
	val []interface{}
}

// Enqueue value
func (queue *Queue) Enqueue(val interface{}) {
	queue.val = append(queue.val, val)
}

// Dequeue value
func (queue *Queue) Dequeue() interface{} {
	res := queue.val[0]
	queue.val = queue.val[1:len(queue.val)]
	return res
}

// IsEmpty return true when queue is empty
func (queue *Queue) IsEmpty() bool {
	return len(queue.val) == 0
}

C++: #include<bits/stdc++.h>
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define int long long
#define vec(a,n) vector<int> (a)((n));
#define Vec(a,n) vector<string> (a)((n));
#define twovec(a,n,m) vector<vector<int>> a(n,vector<int>(m,0));
#define Twovec(a,n,m) vector<vector<double>> a(n,vector<double>(m,0));
#define P pair<int,int>
#define All(a) (a).begin(),(a).end()
#define Sort(a) sort(All(a));
#define Reverse(a) reverse(All(a));
#define PQ(n) priority_queue<P,vector<P>,greater<P>> (n)
#define pq(n) priority_queue<int> (n)
#define print(a) cout << (a) << endl
#define printD(a) cout << setprecision(15) << (a) << endl;
using namespace std;
int max_int = 2147483647;
int prime = 10e9+7;
void Debug(auto a);
int nibul(auto a,auto b);
int nibuu(auto a,auto b);
void input(vector<auto>& a,int n);
double PI = 3.14159265358979;
int n;

struct Edge{
    int from,to,cost;
    bool operator<(const Edge& another) const{
        return cost < another.cost;
    }
    bool operator>(const Edge& another) const{
        return cost > another.cost;
    }
};

class dGrapf{
    vector<vector<P>> grapf;
    vector<int> d;
    bool loop = false;
    public:
    dGrapf(int n){
        this->grapf.resize(n);
        this->d.resize(grapf.size(),max_int);
    }
    dGrapf(){
        this->grapf.resize(10e6);
        this->d.resize(grapf.size(),max_int);
    }
    /* 辺の元、先、コストの順
     */
    void edge(int parent,int child,int weight=1){
        P p = P(child,weight);
        grapf[parent].push_back(p);
    }
    void dijkstra(int n){
        d[n] = 0;
        PQ(que);
        que.emplace(0,n);
        while(!que.empty()){
            P p = que.top();
            que.pop();
            int v = p.second;
            if(d[v] < p.first) continue;
            for(P e: grapf[v]){
                if(d[e.first] > d[v]+e.second){
                    d[e.first] = d[v]+e.second;
                    que.emplace(d[e.first],e.first);
                }
            }
        }
    }
    void bellmanford(int n){
        fill(d.begin(), d.end(), max_int);
        d[n] = 0;
        bool update = true;
        int cnt = 0;
        while(update){
            update = false;
            REP(i,grapf.size()){
                REP(j,grapf[i].size()){
                    if(d[i] != max_int && d[grapf[i][j].first] > d[i] + grapf[i][j].second){
                        d[grapf[i][j].first] = d[i] + grapf[i][j].second;
                        update = true;
                    }
                }
            }
            cnt++;
            if(cnt > grapf.size()){
                loop = true;
                return;
            }
        }
    }
    vector<int> topological_sort(){
        vector<int> indeg(grapf.size(),0);
        REP(i,grapf.size()){
            for(auto v:grapf[i]){
                indeg[v.first]++;
            }
        }
        queue<int> que;
        REP(i,indeg.size()){
            if(indeg[i] == 0){
                que.push(i);
            }
        }
        vector<int> ans;
        while(!que.empty()){
            int u = que.front();
            que.pop();
            ans.push_back(u);
            for(auto v:grapf[u]){
                indeg[v.first]--;
                if(indeg[v.first] == 0) que.push(v.first);
            }
        }
        if(ans.size() != grapf.size()) loop = true;
        return ans;
    }

    void print_AOJ(){
        REP(i,d.size()){
            if(d[i] == max_int){
                cout << i+1 << " -1\n";
            }
            else{
                cout << i+1 << " " << d[i] << endl;
            }
        }
    }
    void De(){
        REP(i,grapf.size()){
            cout << "{";
            for(P p:grapf[i]){
                cout << "{" << p.first << "," << p.second << "}";
            }
            cout << "}\n";
        }
        Debug(d);
    }
};


signed main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cin >> n;
    dGrapf g(n);
    REP(i,n){
        int u,k;
        cin >> u >> k;
        u--;
        REP(j,k){
            int tmp;
            cin >> tmp;
            tmp--;
            g.edge(u,tmp);
        }
    }
    g.dijkstra(0);
    g.print_AOJ();
    return 0;
}

void Debug(auto a){
    cout << "{ ";
    for(auto b: a){
        cout << b << " ";
    }
    cout << "}" << endl;
}

//key以上の初めてのitr
int nibul(auto a,auto b){return lower_bound(All(a),b) - a.begin();}
//key以下の最後のitr
int nibuu(auto a,auto b){return upper_bound(All(a),b) - a.begin()-1;}

void input(vector<auto>& a,int n){
    REP(i,n){
        cin >> a[i];
    }
}

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

using namespace std;

int main(){
    int n;
    cin >> n;
    
    int g[102][102];
    int d[102];
    for(int i=1; i<=n; i++){
        for(int j=1; j<=n; j++){
            g[i][j] = 0;
        }
        d[i] = -1;
    }
    
    int u,k;
    for(int i=0; i<n; i++){
        cin>>u>>k;
        for(int j=0; j<k; j++){
            int v;
            cin>>v;
            g[u][v] = 1;
        }
    }

    int q[102];
    int h = 0, t = h + 1;
    q[h] = 1;
    d[ q[h] ] = 0;
    while(h != t){
        u = q[h++];
        for(int i=1; i<=n; i++){
            if(g[u][i] == 1 && d[i] == -1){
                g[u][i] = 0;
                d[i] = d[u]+1; 
                q[t++] = i;
              
            }
        }
    }
    
    for(int i=1; i<=n; i++){
        cout<< i << " " << d[i] << endl;
    }
    
    return 0;
}

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

int main() {
  int n;
  cin >> n;

  vector<vector<int>> M(n, vector<int>(n));
  for (int i = 0; i < n; i++) {
    int node;
    int d;
    cin >> node >> d;
    node--;

    for (int j = 0; j < d; j++) {
      int tmp;
      cin >> tmp;
      tmp--;
      M[i][tmp] = 1;
    }
  }

  vector<int> res(n);
  vector<int> e(n);

  queue<int> q;
  q.push(0);

  while (!q.empty()) {
    int num = q.front();
    q.pop();

    int cnt = res[num] + 1;

    for (int i = 0; i < M[num].size(); i++) {
      if (M[num][i] == 0) { continue; }
      if (e[i] == 1) { continue; }
      q.push(i);
      e[i]   = 1;
      res[i] = cnt;
    }
  }

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