Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

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

const int inf = 1<<29;
int n;
vector<int> d(110, inf);
vector< vector<bool> > G(110, vector<bool>(110, false));

void bfs(int s){

    queue<int> q;
    d[s] = 0;
    q.push(s);

    while(!q.empty()){
        int now = q.front(); q.pop();
        for(int i=1; i<=n; ++i){
            if(G[now][i] == true && d[now]+1 < d[i]){
                d[i] = d[now] + 1;
                q.push(i);
            }
        }
    }

}

int main(){
    cin >> 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[id][v] = true;
        }
    }

    bfs(1);

    for(int i=1; i<=n; ++i){
        cout << i << " ";
        if(d[i] == inf) cout << -1;
        else cout << d[i];
        cout << endl;
    }
}

C++: #include<iostream>
#include<queue>
#include<algorithm>

#define N 1000
#define UNDEFINED -1

int n, u, k, v;
int G[N][N];
std::queue<int> Q;
int d[N];

int main() {
    for(int i = 0; i < N; i++) {
        d[i] = UNDEFINED;
        for(int j = 0; j < N; j++) {
            G[i][j] = 0;
        }
    }

    std::cin >> n;
    for(int i = 0; i < n; i++) {
        std::cin >> u >> k;
        for(int j = 0; j < k; j++) {
            std::cin >> v;
            G[u][v] = 1;
        }
    }

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

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

    return 0;
}

C++: /*
Breadth First Search(https://onlinejudge.u-aizu.ac.jp/#/problems/ALDS1_11_C)
*/
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <map>
#include <set>
#include <vector>
#include <stack>
#include <queue>
#include <bitset>
#include <algorithm>
#include <numeric>
#include <functional>
using namespace std;

#define Rep(b, e, i) for(int i = b; i <= e; i++)
#define rep(n, i) Rep(0, n-1, i)
#define pb(v) push_back(v)
#define ENJYU std::ios::sync_with_stdio(false);std::cin.tie(0);

const int MAX = 128;

//隣接リスト
vector <int> adj[MAX];
//頂点１からの距離
int d[MAX];

void solve(void){
	//init
	ENJYU;
	memset(d, -1, sizeof(d));
	//input
	int N;
	cin >> N;
	rep(N, i) {
		int u, k;
		cin >> u >> k;
		u--;
		rep(k, i) {
			int v;
			cin >> v;
			v--;
			adj[u].pb(v);
		}
	}
	//bfs
	queue <int> q;
	q.push(0);
	d[0] = 0;
	while (!q.empty()) {
		int n = q.front();
		q.pop();
		for (int nv : adj[n]) {
			if (d[nv] >= 0) {
				continue;
			}
			d[nv] = d[n] + 1;
			q.push(nv);
		}
	}

	rep(N, i) cout << i+1 << ' ' << d[i] << endl;

}

int main(void){
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}

C++: #include<algorithm>
#include<bitset>
#include<cassert>
#include<cfloat>
#include<climits>
#include<cmath>
#include<deque>
#include<functional>
#include<iomanip>
#include<iostream>
#include<map>
#include<queue>
#include<set>
#include<stack>
#include<string>
#include<unordered_map>
#include<unordered_set>
#include<utility>
#include<vector>
#include<complex>
#include<list>
#include<cstdio>

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)


using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;




const int INF = 1e9 + 7;


/******************************************************************************************/



vector<int> G[105];
int dist[105];


int main() {

	cin.tie(0);
	ios::sync_with_stdio(false);
	cout << fixed << setprecision(10);

	int n;
	cin >> n;

	for (int i = 0; i < 105; i++)
	{
		dist[i] = INF;
	}

	for (int i = 0; i < n; i++)
	{
		int node, out;
		cin >> node >> out;
		for (int j = 0; j < out; j++)
		{
			int c;
			cin >> c;
			G[node].push_back(c);
		}
	}


	queue<int> que;

	que.push(1);
	dist[1] = 0;

	while (!que.empty()) {

		int now = que.front();
		que.pop();

		if (dist[now] == INF)continue;
		for (int nxt : G[now]) {

			if (dist[nxt] > dist[now] + 1) {
				dist[nxt] = dist[now] + 1;
				que.push(nxt);
			}
		}
	}

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