Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

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

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

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
		}
	}
}

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

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

#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define FOR(i,n,m) for(int i=(int)(n); i<=(int)(m); i++)
#define RFOR(i,n,m) for(int i=(int)(n); i>=(int)(m); i--)
#define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++)
#define RITR(x,c) for(__typeof(c.rbegin()) x=c.rbegin();x!=c.rend();x++)
#define setp(n) fixed << setprecision(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 (a>b) { a=b; return 1; } return 0; }

#define ll long long
#define vll vector<ll>
#define vi vector<int>
#define pll pair<ll,ll>
#define pi pair<int,int>

#define all(a) (a.begin()),(a.end())
#define rall(a) (a.rbegin()),(a.rend())
#define fi first
#define se second
#define pb push_back
#define mp make_pair
#define ins insert

using namespace std;

//-------------------------------------------------
//--Graph Template
//-------------------------------------------------
template<class E>
struct Graph
{
    vector<vector<E> > adj;
    Graph(int N):adj(N){}
    virtual void add_edge(int v, E e){adj[v].push_back(e);}
    vector<E>& operator[](int v){return adj[v];}
    inline int size(){return adj.size();}
};

struct NormalEdge {
    int to;
    NormalEdge(int to):to(to){}
};

struct UWGraph : public Graph<NormalEdge>
{
    UWGraph(int N):Graph(N){}
    void add_edge(int v, int e){adj[v].push_back({e});}
};

//-------------------------------------------------
//--Dist BFS
//-------------------------------------------------
template<class E>
vector<int> distBFS(Graph<E> &G, int s)
{
    vector<int> dist(G.size(),-1); dist[s]=0;
    queue<int> que; que.push(s);
    while(!que.empty()){
        int v = que.front(); que.pop();
        for(auto e:G[v]){
            if (dist[e.to]!=-1) continue;
            dist[e.to]=dist[v]+1;
            que.push(e.to);
        }
    }
    return dist;
}

//-------------------------------------------------

int main(void)
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    int N; cin>>N;
    UWGraph G(N);
    rep(i,N){
        int u,k; cin>>u>>k; u--;
        rep(i,k){
            int v; cin>>v; v--;
            G.add_edge(u,v);
        }
    }
    auto dist = distBFS(G,0);
    rep(i,N){
        cout<<i+1<<" "<<dist[i]<<"\n";
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;
#define MAX_V 110

int main() {
    
    vector<vector<int>> G(MAX_V);
    int n; cin >> n;
    for(int i=0; i<n; i++){
        int v, k; cin >> v >> k;

        for(int j=0; j<k; j++){
            int u; cin >> u;
            G[v].push_back(u);
        }
    }

    vector<int> dist(MAX_V, -1);
    dist[1] = 0;

    queue<int> q;
    q.push(1);
    while(!q.empty()){

        int v = q.front();
        q.pop();

        for(int i=0; i<G[v].size(); i++){
            int u = G[v][i];
            if(dist[u] == -1){
                dist[u] = dist[v] + 1;
                q.push(u);
            }
        }
    }

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

C++: #include <iostream>
#include <string>
#include <vector>


#define ALREADY 1
#define YET 0

int *passed;
int *distance_ps;

using namespace std;


void bfs(vector< vector<int> > a, int i, int dis){
  // i?????????vector<int>??????????????¢?????????
  dis++;
  vector<int> ai = a[i];
  int n = ai.size();
  // cout << "i: " << i << ",n: " << n << endl;
  for(int j=0;j<n;j++){
    int nexti=ai[j]-1;
    
    if(passed[nexti]==YET || distance_ps[nexti]>dis){
      passed[nexti]=ALREADY;
      distance_ps[nexti]=dis;
      bfs(a, nexti, dis);
    }
  }
}

int main(){
  int n;
  cin >> n;
  vector< vector<int> > a;
  for(int i=0;i<n;i++){
    int u;
    int k;
    cin >> u >> k;
    vector<int> tmpa;
    for(int j=0;j<k;j++){
      int tmp;
      cin >> tmp;
      tmpa.push_back(tmp);
    }
    a.push_back(tmpa);
  }
  
  int a2[n][n];
  passed = new int[n];
  distance_ps = new int[n];
  
  for(int i=0;i<n;i++){
    passed[i] = 0;
    distance_ps[i] = 1000;
  }

  distance_ps[0]=0;
  bfs(a, 0, 0);

  for(int i=0;i<n;i++){
    if(passed[i]==YET){
      distance_ps[i] = -1;
    }
  }
  distance_ps[0]=0;
  
  for(int i=0;i<n;i++){
    cout << i+1 << " " << distance_ps[i] << endl;
  }
  
  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      a2[i][j]=0;
    }
  }
  
  for(int i=0;i<n;i++){
    for(int j=0;j<(int)a[i].size();j++){
      a2[i][a[i][j]-1] = 1;
    }
  }

  for(int i=0;i<n;i++){
    for(int j=0;j<n;j++){
      // if(j!=0)cout << " ";
      // cout << a2[i][j];
    }
    // cout << endl;
  }
      
  
}

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

template<class T>
struct Edge{
	int from,to;
	T cost;
	Edge(int to,T cost) : to(to),cost(cost){}
	Edge(int from,int to,T cost) : from(from),to(to),cost(cost){}
};

template<class T>
using WeightedGraph = vector<vector<Edge<T>>>;
using Graph = vector<vector<int>>;
template<class T>
using Matrix = vector<vector<T>>;

template<class T = int>
vector<T> BFS(const Graph &G,int source = 0){
	vector<T> dist(G.size(),-1);
	queue<int> que;
	dist[source] = 0;
	que.push(source);
	for(T d = 0;;d++){
		int siz = que.size();
		if(siz == 0) break;
		for(int i = 0;i < siz;i++){
			int v = que.front();que.pop();
			for(int to : G[v]){
				if(dist[to] == -1){
					dist[to] = d + 1;
					que.push(to);
				}
			}
		}
	}
	return dist;
}

signed main(){
	int n;
	cin >> n;
	Graph G(n);
	for(int i = 0;i < n;i++){
		int u,k;
		cin >> u >> k;
		for(int j = 0;j < k;j++){
			int v;
			cin >> v;
			G[u - 1].push_back(v - 1);
		}
	}
	auto dist = BFS(G,0);
	for(int i = 0;i < n;i++) cout << i + 1 << " " << dist[i] << endl;
}