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++: //push(),pop():C++ではstackと統一されいる
//front():先頭の要素が何かを返す
//back():末尾の要素が何であるかを返す
//empty():キューが空であるかどうかを調べる
//size():要素数を調べる
#include <iostream>
#include <queue>
using namespace std;
#define MAX 101
#define WHITE 0
#define GRAY 1
#define BLACK 2
static const int INFTY = (1<<21);

int G[MAX][MAX],color[MAX],d[MAX],num;

void bfs(int s){
  int u;
  queue<int> Q; //Qを使うことでエンキュー、デキューの操作が容易になる
  for(int i=1; i<=num; i++) {
    d[i] = INFTY;
  }
  Q.push(s);
  d[s] = 0;
  while(!Q.empty()){
    u = Q.front();
    Q.pop();
    for(int v=1; v<=num; v++){
      if(G[u][v] == 0) continue;
      if(d[v] != INFTY) continue;
      d[v] = d[u] + 1;
      Q.push(v);
    }
  }
}


int main(){
  int i,j,u,k,v;

  scanf("%d",&num);
  for(i=1; i<=num; i++){
    color[i] = WHITE;
    for(j=1; j<=num; j++){
      G[i][j] = 0;
    }
  }
  for(i=1; i<=num; i++){
    scanf("%d%d",&u,&k);
    for(j=1; j<=k; j++){
      scanf("%d",&v);
      G[u][v] = 1;
    }
  }

  bfs(1);

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

  return 0;
}

C++: #define _GLIBCXX_DEBUG

#include"bits/stdc++.h"
using namespace std;

//loops
#define REP(i,n) for(int i=0;i<(ll)(n);i++)
#define REPD(i,n) for(int i=(ll)(n)-1;i>=0;i--)
#define OneToN(i,n) for(int i=1;i<(ll)(n+1);i++)
#define ZeroToN(i,n) for(int i=0;i<(ll)(n+1);i++)
#define AToB(i,a,b) for(int i=a;i<(ll)(b+1);i++)
#define FOR(i,a,b) for(int i=(a);i<=(b);i++)
#define FORD(i,a,b) for(int i=(a);i>=(b);i--)

//bitsearch
#define BITSEARCH(bit, n) for (int bit = 0; bit < (1<<n); ++bit)
#define isOne(bit, i) bit & (1<<i)


//arrays
#define ALL(x) (x).begin(),(x).end() //sortなどの引数を省略したい
#define SIZE(x) ((ll)(x).size()) //sizeをsize_tからllに直しておく
#define add push_back


#define remove_unique(v) v.erase(unique(ALL(v)), v.end())

//pair
#define fir first
#define sec second

//types
#define ll long long
#define vec vector
#define cord2d pair<int,int>
//UNCOMMENT WHEN NEEDED
//#define int ll

//input
template <class T> T get(){ T s; cin >> s; return(s);}
#define gi get<int>()
#define gs get<string>()

template <class T> vector<T> getv(int n) { vec<T> v(n); REP(i, n) cin >> v[i]; return v; }
#define gim(n) getv<int>(n)
#define gsm(n) getv<string>(n)

//output
void print(int a){ cout << a << endl; }
void print(long long a){ cout << a << endl; }
void print(string a){ cout << a << endl; }
void print(char a){ cout << a << endl; }
void print(double a){ cout << a << endl; }
void print(double a, int dig){ cout << std::setprecision(dig) << a << endl; }

template <class T>ostream &operator<<(ostream &o,const vector<T>&v)
{o<<"{";for(int i=0;i<(int)v.size();i++)o<<(i>0?", ":"")<<v[i];o<<"}";return o;}

template <class T = int>
void print(vec<T> v){ cout << v << endl; }

template <class T = int>
void print2dVec(vec<vec<T>> v2d){for(vec<T> v: v2d) {print(v);}}

void YesNo1(bool i = true){ return print(i?"Yes":"No"); }
void YESNO2(bool i = true){ return print(i?"YES":"NO"); }

//debug output
#define var_name(var) #var
template <class T> void debug(T &var, int nest = 0, string before = "") { cout << string("          ", nest) << before; print(var); }

//name replacement
#define y0 y0__
#define y1 y1__
#define j0 j0__
#define j1 j1__

//bool lambdas
#define lamb(exp) [](auto i){return exp;}
#define isEven [](int i){return i % 2 == 0;}
#define isOdd [](int i){return i % 2 != 0;}

//constants
const ll INF = 1e18;
const int MOD = 10000007;

//maths
int factorial(int k){ int sum = 1; for (int i = 1; i <= k; ++i) { sum *= i; } return sum; }
int gcd(int a, int b) {
    if (b == 0)
        return a;
    return gcd(b, a % b);
}

////////////////////

void Main() {
    //code here

    int n = gi;
    vec<vec<int>> graph(n);
    REP(i, n) {
        //print(i);
        int u = gi;
        int k = gi;
        REP(j, k) {
            graph[u-1].add(gi-1);
        }
    }

    //幅優先探索
    // BFS のためのデータ構造
    vector<int> dist(n, -1); // 全頂点を「未訪問」に初期化
    queue<int> que;

    // 初期条件 (頂点 0 を初期ノードとする)
    dist[0] = 0;
    que.push(0); // 0 を橙色頂点にする

    // BFS 開始 (キューが空になるまで探索を行う)
    while (!que.empty()) {
        int v = que.front(); // キューから先頭頂点を取り出す
        que.pop();

        // v から辿れる頂点をすべて調べる
        for (int nv : graph[v]) {
            if (dist[nv] != -1) continue; // すでに発見済みの頂点は探索しない

            // 新たな白色頂点 nv について距離情報を更新してキューに追加する
            dist[nv] = dist[v] + 1;
            que.push(nv);
        }
    }

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

signed main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    Main();
}