Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

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

typedef unsigned long long ull;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<double, double> pdd;
typedef vector<vector<ll>> Graph;

const ll mod = 1e9 + 7;
//const ll mod = 998244353;

#define REP(i,n) for(ll i=0;i<(ll)n;i++)
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define spa << " " <<
#define fi first
#define se second

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; }

template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){
os << "(" << v.first << ", " << v.second << ")"; return os;
}
template<class T> ostream& operator << (ostream& os, const vector<T> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << " ";} os << v[i];} return os;
}
template<class T> ostream& operator << (ostream& os, const vector<vector<T>> v){
for(int i = 0; i < (int)v.size(); i++){if(i > 0){os << endl;} os << v[i];} return os;
}

template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<endl;}};
template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];
for(ll i=1;i<n;i++)cerr spa v[i];
cerr<<endl;};

string num2bit(ll num, ll len){
    string bit = "";
    REP(i, len){
    bit += char('0'+(num>>i & 1));
    }
    return bit;
}

vector<int> graph_bfs(Graph &G, vector<ll> &s){
    const int N = G.size();
    vector<int> dist(N, -1);
    queue<int> qu;

    // initialization
    for(auto v: s){
        qu.push(v);
        dist[v] = 0;
    }

    while(!qu.empty()){
        int now = qu.front();qu.pop();
        for(auto next: G[now]){
            if(dist[next] != -1) continue;
            dist[next] = dist[now] + 1;
            qu.push(next);
        }
    }

    return dist;
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    ll n;
    cin >> n;
    Graph G(n);
    REP(i, n){
        ll u, k;
        cin >> u >> k;
        u--;
        REP(j, k){
            ll v;
            cin >> v;
            v--;
            G[u].push_back(v);
        }
    }

    vector<ll> s = {0};

    auto dist = graph_bfs(G, s);

    REP(i, n){
        cout << i+1 << " " << dist[i] << endl;
    }

    return 0;
}

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

using namespace std;

#define REP(var, count) for(int var=0; var<count; var++)

int main(void) {
	int N;
	cin >> N;
	
	vector<int> rin[105];
	int ans[105];
	
	REP(i, N) {
		int u, k;
		cin >> u >> k;
		
		REP(j, k) {
			int c;
			cin >> c;
			
			rin[u].push_back(c);
		}
		
		ans[i] = -1;
	}
	ans[N] = -1;
	
	ans[1] = 0;
	queue<int> que;
	que.push(1);
	
	while(que.size()) {
		int s = que.front();
		que.pop();
		
		//cerr << "checking " << s << endl;
		
		REP(j, rin[s].size() ) {
			//cerr << "edge to " << rin[s][j] << endl;
			if ( ans[rin[s][j]] == -1 ) {
				ans[rin[s][j]] = ans[s] + 1;
				que.push(rin[s][j]);
			}
		}
	}
	
	for(int i=1; i<=N; i++) {
		cout << i << " " << ans[i] << endl;
	}
}