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++: /**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author champon
 */

#include <iostream>
#include <fstream>
#include<bits/stdc++.h>
#define se cout << "test ok" << endl;
#define sp << " " <<
#define enl "\n"
using namespace std;
using ll=long long;
using ld=long double;
ll mod = ll(1e9)+7;
ll inf = ll(1e18);
void bl(bool b, ostream& out=cout){ out << (b ? "Yes" : "No") << endl; }
void bl2(bool b, ostream& out=cout){ out << (b ? "YES" : "NO") << endl; }
template<typename T> inline bool chmax(T &a, T b){ if(a<b){a=b; return true;} return false; }
template<typename T> inline bool chmin(T &a, T b){ if(a>b){a=b; return true;} return false; }
int dx[] = {1, 0, -1, 0, 1, -1, 1, -1};
int dy[] = {0, 1, 0, -1, 1, -1, -1, 1};

#ifndef INCLUDE_DEBUG_HPP
#define INCLUDE_DEBUG_HPP

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

namespace dbg {
    using ll = long long;

    class Debug {
    public:
        Debug(){}
        template<typename T>
        void vd(vector<T> vec);
        template<typename T>
        void vd2(vector<vector<T>> vec);
        template<typename T>
        void ad(T *arr, ll n);
        template<typename T, size_t N>
        void ad2(T (&arr)[N], ll n);
        template<typename T>
        void md(T mp);
    };

    template<typename T>
    void Debug::vd(vector<T> vec) {
        for (auto vv : vec) cout << vv << " ";
        cout << endl;
    }

    template<typename T>
    void Debug::vd2(vector<vector<T>> vec) {
        for (auto vv : vec) {
            for (auto vvv : vv) cout << vvv << " ";
            cout << endl;
        }
    }

    template<typename T>
    void Debug::ad(T *arr, ll n) {
        for (int i = 0; i <= n; i++) cout << arr[i] << " ";
        cout << endl;
    }

    template<typename T, size_t N>
    void Debug::ad2(T (&arr)[N], ll n) {
        for (int i = 0; i <= N; i++) for (int j = 0; j <= n; j++) cout << arr[i][j] << " ";
        cout << endl;
    }

    template<typename T>
    void Debug::md(T mp) {
        cout << "key : value" << endl;
        for (auto const &m : mp) cout << m.first << " : " << m.second << endl;
        cout << endl;
    }

}

#endif //INCLUDE_DEBUG_HPP

using dbg::Debug;
Debug debug;

class a {
public:
	void solve(std::istream& in, std::ostream& out) {
	    int n;
	    in >> n;
	    int u, k;
	    vector<vector<int>> g(n);
	    for(int i=0; i<n; i++){
            in >> u >> k;
            --u;
            int v;
            for(int j=0; j<k; j++){
                in >> v;
                g[u].push_back(--v);
            }
	    }

	    queue<int> q;
	    vector<ll> dist(n, inf);
	    q.push(0);
	    dist[0] = 0;
	    while(!q.empty()){
	        int from = q.front();
	        q.pop();
	        for(auto& to : g[from]){
                if(dist[to] > dist[from] + 1){
                    dist[to] = dist[from] + 1;
                    q.push(to);
                }
	        }
	    }

	    for(int i=0; i<n; i++){
	        out << i+1 sp (dist[i]==inf ? -1 : dist[i]) << enl;
	    }
	}
};


int main() {
    cin.tie(nullptr);
    ios_base::sync_with_stdio(false);
	a solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}

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

int main(){
    int n;
    cin>>n;
    vector<vector<int>> g(n);
    int u,k,v;
    for(int i=0;i<n;++i){
        cin>>u>>k;
        if(k==0)continue;
        for(int j=0;j<k;++j){
            cin>>v;
            g[i].push_back(v-1);
        }
    }
    vector<int> dist(n,-1);
    queue<int> que;
    dist[0]=0;
    que.push(0);
    while(!que.empty()){
        int q=que.front();
        que.pop();
        for(int nv:g[q]){
            if(dist[nv]!=-1)continue;
            dist[nv]=dist[q]+1;
            que.push(nv);
        }
    }
    for(int i=0;i<n;++i){
        cout<<i+1<<" "<<dist[i]<<endl;
        //if(i<n-1)cout<<""<<endl;
    }
    return 0;
}

C++: /*
** BFS
*/

# include <cstdio>
# include <cstring>
# include <queue>
using namespace std;

const int MAX = 100 + 2;
int n, g[MAX][MAX], d[MAX], c[MAX];

void init() {
    scanf("%d", &n);
    memset(g, 0, sizeof(g));
    memset(c, 0, sizeof(c));

    int u, v, k;
    for (int i = 1; i <= n; i++) {
        d[i] = -1;
        scanf("%d%d", &u, &k);
        while (k--) {
            scanf("%d", &v);
            g[u][v] = 1;
        }
    }
}

void bfs() {
    queue<int> q;
    q.push(1);
    c[1] = 1;
    d[1] = 0;

    while (!q.empty()) {
        int v = q.front();
        q.pop();
        for (int i = 1; i <= n; i++) {
            if (g[v][i] == 1 && c[i] == 0) {
                q.push(i);
                c[i] = 1;
                d[i] = d[v] + 1;
            }
        }
    }
}

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

int main() {
    // freopen("infile", "r", stdin);
    // freopen("outfile", "w", stdout);
    solve();
    return 0;
}

C++: #include<iostream>
#include<queue>
static const int N = 100;
static const int INFTY = (1 << 21);
using namespace std;

int n, M[N][N],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 < n; j++) {
			cin >> v;
			v--;
			M[u][v] = 1;
		}
	}

	bfs(0);

    return 0;
}