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 <iostream>
#include <vector>
#include <map>
#include <queue>
using namespace std;

class Vertex {
public:
    int num;
    bool flag;                  // 以前訪れたかどうか
    vector<int> adj;            // 隣接リスト
};

int dist[101];
void bfs(map<int, Vertex>& graph, Vertex s) {
    queue<Vertex> que;

    dist[s.num] = 0;
    que.push(s);
    while (!que.empty()) {
        Vertex u = que.front(); que.pop();
        for (auto i = 0; i < u.adj.size(); i++) {
            Vertex v = graph[u.adj[i]];
            if (!v.flag) {
                graph[u.adj[i]].flag = true;
                dist[v.num] = dist[u.num]+1;
                que.push(v);
            }
        }
    }
}

int main(void) {
    int n;
    cin >> n;
    for (int i = 0; i < 101; i++) {
        dist[i] = -1;
    }

    map<int, Vertex> graph; // 頂点の番号->頂点
    for (int i = 0; i < n; i++) {
        Vertex v;
        int num, k;
        cin >> num >> k;
        v.flag = false;
        v.num = num;
        for (int j = 0; j < k; j++) {
            int tmp;
            cin >> tmp;
            v.adj.push_back(tmp);
        }
        graph[num] = v;
    }

    bfs(graph, graph[1]);
    for (int i = 1; i <= n; i++) {
        cout << i << " " << dist[i] << endl;
    }

    return 0;
}

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

int main() {
    int n; cin >> n;
    vector<vector<int>> g(n);
    for (int i = 0; i < n; i++) {
        int u, k; cin >> u >> k; u--;
        while (k--) {
            int v; cin >> v; v--;
            g[u].push_back(v);
        }
        sort(g[u].begin(), g[u].end());
    }
    vector<int> d(n, -1);
    d[0] = 0;
    queue<int> q; q.push(0);
    while (q.size()) {
        int v = q.front(); q.pop();
        for (auto x : g[v]) {
            if (d[x] < 0) {
                d[x] = d[v] + 1;
                q.push(x);
            }
        }
    }
	for (int i = 0; i < n; i++) cout << i + 1 << " " << d[i] << endl;
}

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

struct Graph {
    enum Color {WHITE, GRAY, BLACK};
    vector<vector<int>> adj;
    vector<Color> color;
    vector<int> dist;
    Graph(int n) {
        adj.assign(n, vector<int>());
        color.assign(n, WHITE);
        dist.assign(n, -1);
    }
};

int main()
{
    int n;
    cin >> n;
    Graph g(n);
    for (int i = 0; i < n; i++) {
        int id, k;
        cin >> id >> k;
        for (int j = 0; j < k; j++) {
            int v;
            cin >> v;
            g.adj[id - 1].push_back(v - 1);
        }
    }

    queue<int> q;
    g.color[0] = Graph::GRAY;
    g.dist[0] = 0;
    q.push(0);
    while (!q.empty()) {
        int u = q.front();
        q.pop();
        for (auto v : g.adj[u]) {
            if (g.color[v] == Graph::WHITE) {
                g.color[v] = Graph::GRAY;
                g.dist[v] = g.dist[u] + 1;
                q.push(v);
            }
        }
        g.color[u] = Graph::BLACK;
    }

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

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

#define MAX_NODE 10000
#define INF 1000000000

using namespace std;

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

int bfs(int n, int start){
	queue<int> que;
	for(int i=0;i<n;i++){
		d[i]=(i==start)?0:-1;
	}
	que.push(start);
	while(que.empty()==0){
		int from=que.front();
		que.pop();
		for(int i=0;i<adj[from].size();i++){
			int to=adj[from][i];
			if(d[to]==-1){
				d[to]=d[from]+1;
				que.push(to);
			}
		}
	}
}	

int main(){
	int n,u,k,v;
	cin>>n;
	for(int i=0;i<n;i++){
		cin>>u>>k;
		for(int j=0;j<k;j++){
			cin>>v;
			v--;
			adj[u-1].push_back(v);
		}
	}
	bfs(n,0);
	for(int i=0;i<n;i++){
		cout<<i+1<<" "<<d[i]<<endl;
	}
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
#include<queue>
using namespace std;
#define N 1000
bool M[N][N];

int main(){
    int n,u,k,v;
    queue<int> Q;

    cin >> n;
    for(int i=0;i<n;i++){
        cin >> u >> k;
        u--;
        for(int j=0;j<k;j++){
            cin >> v;
            v--;
            M[u][v]=true;
        }
    }

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

    for(int i=0;i<n;i++){
        printf("%d %d\n",i+1,d[i]);
    }

    return 0;
}

C++: #include <bits/stdc++.h>
#define MAX 100
using namespace std;

int n;
vector<int> G[MAX];
int d[MAX];

int main()
{
	cin >> n;
	for (int i = 0; i < n; i++) {
		d[i] = -1;
	}
	for (int i = 0, u, k; i < n; i++) {
		cin >> u >> k;
		for (int j = 0, v; j < k; j++) {
			cin >> v;
			G[u - 1].push_back(v - 1);
		}
	}
	queue<int> q;
	q.push(0);
	d[0] = 0;
	while (!q.empty()) {
		for (int &v : G[q.front()]) {
			if (d[v] == -1) {
				q.push(v);
				d[v] = d[q.front()] + 1;
			}
		}
		q.pop();
	}

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

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

using namespace std;
using ll = long long;

int n;
vector<vector<int>> hen;
vector<bool> seen;
vector<int> dist;

void bfs()
{
    queue<int> que;
    que.push(0);
    dist[0] = 0;
    seen[0] = true;
    while(que.size())
    {
        auto cur = que.front();
        que.pop();
        for(auto i : hen[cur]){
            if(seen[i])continue;
            seen[i] = true;
            dist[i] = dist[cur] + 1;
            que.push(i);
        }
    }
}




int main()
{
    cin >> n;
    hen.resize(n);
    dist.resize(n, -1);
    seen.resize(n);
    for(int i = 0; i < n; i++){
        int u, k; cin >> u >> k; u--;
        for(int j = 0; j < k; j++){
            int tmp; cin >> tmp; tmp--;
            hen[u].push_back(tmp);
        }
    }
    bfs();

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


}