Go: package main

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

var distance []int

type queue struct {
	q    []int
	head int
	tail int
}

func (q *queue) push(n int) {
	q.q[q.tail] = n
	q.tail++
}

func (q *queue) pop() int {
	q.head++
	return q.q[q.head-1]
}

func (q *queue) isEmpty() bool {
	return q.head == q.tail
}

func makeAdjList() [][]int {
	var n int
	fmt.Scanf("%d", &n)

	adj := make([][]int, n)
	for i := 0; i < n; i++ {
		adj[i] = make([]int, n)
	}

	sc := bufio.NewScanner(os.Stdin)
	for i := 0; i < n; i++ {
		sc.Scan()
		nodeInfo := strings.Split(sc.Text(), " ")
		outDegree, _ := strconv.Atoi(nodeInfo[1])

		if outDegree > 0 {
			for k := 0; k < outDegree; k++ {
				j, _ := strconv.Atoi(nodeInfo[k+2])
				j-- // convert 1 based to 0 based
				adj[i][j] = 1
			}
		}
	}

	return adj
}

func bfs(graph [][]int, s int) {
	distance = make([]int, len(graph))

	infty := -1
	for i := 0; i < len(distance); i++ {
		distance[i] = infty
	}
	distance[s] = 0

	q := &queue{make([]int, 1000), 0, 0}
	q.push(s)

	for !q.isEmpty() {
		u := q.pop()
		for i := 0; i < len(graph); i++ {
			if graph[u][i] == 0 {
				continue // u, i間に辺がない場合
			}
			if distance[i] != infty {
				continue // 訪問済みの場合
			}
			// 訪問するnodeの始点からの距離を設定し、訪問キューに入れる
			distance[i] = distance[u] + 1
			q.push(i)
		}
	}

	// print distance
	for i, d := range distance {
		fmt.Printf("%d %d\n", i+1, d)
	}
}

func main() {
	adj := makeAdjList()
	bfs(adj, 0)
}

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;
}