Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve
const INFTY = (1 << 21)
const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 頂点1から頂点iまでの距離
var color, d [MAX]int

func bfs(s int) {
	var q []int
	q = append(q, s)
	for i := 0; i < n; i++ {
		d[i] = INFTY
	}
	//sは開始点なので、0をいれる
	d[s] = 0

	//キューが空になるまで、以下を繰り返す
	for len(q) > 0 {
		u := q[0]
		q = q[1:]
		for v := 0; v < n; v++ {
			if M[u][v] == 0 {
				continue
			}
			if d[v] != INFTY {
				continue
			}
			d[v] = d[u] + 1
			q = append(q, v)
		}
	}

	for i := 0; i < n; i++ {
		fmt.Printf("%d ", i+1)
		if d[i] == INFTY {
			fmt.Printf("%d\n", -1)
		} else {
			fmt.Printf("%d\n", d[i])
		}
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	bfs(0)

}

C++: #include <bits/stdc++.h>
#define rep(i,n) for (int i = (0); i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define show(x) cout << #x << " = " << (x) << endl
#define show2(x,y) cout << #x << " = " << (x) << ", " << #y << " = " << (y) << endl
#define show3(x,y,z) cout << #x << " = " << (x) << ", " << #y << " = " << (y) <<  ", " << #z << " = " << (z) << endl
#define showv(v) rep(i,v.size()) printf("%d%c", v[i], i==v.size()-1?'\n':' ')
#define showv2(v) rep(j,v.size()) showv(v[j])
#define showt(t,n) rep(i,n) printf("%d%c", t[i], i==n-1?'\n':' ')
#define showt2(t,r,c) rep(j,r) showt(t[j],c)
#define showvp(p) rep(i,p.size()) printf("%d %d\n", p[i].first, p[i].second)
#define printv(v) rep(i,v.size()) printf("%d\n", v[i])
#define printt(t,n) rep(i,n) printf("%d\n", t[i])
#define incl(v,x) (find(all(v),x)!=v.end())
#define incls(s,c) (s.find(c)!=string::npos)
#define lb(a,x) distance((a).begin(),lower_bound(all(a),(x)))
#define ub(a,x) distance((a).begin(),upper_bound(all(a),(x)))
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define bit(n,k) ((n>>k)&1) // nのk bit目
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define uni(x) x.erase(unique(all(x)),x.end())
#define SP << " " <<
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vs = vector<string>;
using P = pair<int, int>;
using T = tuple<int, int, int>;
using vp = vector<P>;
using vt = vector<T>;
const int mod = 1000000007;
const double EPS = 1e-9;
//const long double EPS = 1e-14;
const int INF = (1<<30)-1;
const ll LINF = (1LL<<62)-1;
#define dame { puts("No"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
inline int in() { int x; cin >> x; return x;}
inline ll lin() { ll x; cin >> x; return x;}
inline char chin() { char x; cin >> x; return x;}
inline string stin() { string x; cin >> x; return x;}
inline double din() { double x; cin >> x; return x;}
//template<class T = int> inline T in() { T x; cin >> x; return (x);}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
char itoa(int n) { return n + '0';}
ll gcd(ll a, ll b) { return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}

int main () {
  int n = in();
  vi to[n];
  rep(i,n) {
    int u = in()-1;
    int k = in();
    rep(j,k) to[u].pb(in()-1);
  }

  vi d(n,-1);
  queue<int> q;
  d[0] = 0;
  q.push(0);
  while (!q.empty()) {
    int v = q.front(); q.pop();
    for (int u : to[v]) {
      if (d[u] != -1) continue;
      d[u] = d[v] + 1;
      q.push(u);
    }
  }

  rep(i,n) printf("%d %d\n", i+1, d[i]);
  return 0;
}

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

using namespace std;
static const int N = 100;
static const int INFTY = (1<<21);

int n,M[N][N];
int 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<k; j++){
      cin>>v;
      v--;
      M[u][v] = 1;
    }
  }
  bfs(0);

  return 0;
}

C++: #include <stdio.h>
#include <iostream>
using namespace std;

class Adjl{
private:
	int u;
	int k;
	Adjl **next;
	int check_id;
public:
	Adjl(int u);
	~Adjl(){ if (next != NULL) delete[] next; }
	void setV(int k, Adjl *vk);
	int breadthFirstSearch(int id);
	void print(int id);
};

Adjl::Adjl(int u)
{
	this->u = u;
	k = 0;
	next = NULL;
	check_id = 0;
}

void Adjl::setV(int k, Adjl *vk)
{
	if (this->k == 0) next = new Adjl*[k];
	next[this->k] = vk;
	(this->k)++;
}

int Adjl::breadthFirstSearch(int id)
{
	if (id == check_id) return -1;
	else check_id = id;

	if (id == u) {
		return 0;
	}

	for (int i = 0; i < k; i++) {
		if (id == next[i]->u) {
			return 1;
		}
	}
	int d_min = -1;
	for (int i = 0; i < k; i++) {
		int d = next[i]->breadthFirstSearch(id);
		if (d == -1) continue;
		if (d_min == -1) d_min = d + 1;
		else d_min = min(d_min, d + 1);
	}
	return d_min;
}

void Adjl::print(int id)
{
	cout << id << " " << breadthFirstSearch(id) << endl;
}

int main(void)
{
	int n;
	cin >> n;
	
	Adjl **adjl = new Adjl*[n];
	int check[100] = {0};

	for (int i = 0; i < n; i++) {
		int u, k;
		cin >> u >> k;
		if (check[i] == 0) {
			adjl[i] = new Adjl(u);
			check[i] = 1;
		}
		check[i] = 1;
		for (int j = 0; j < k; j++) {
			int vk;
			cin >> vk;
			if (check[vk - 1] == 0) {
				adjl[vk - 1] = new Adjl(vk);
				check[vk - 1] = 1;
			}
			adjl[i]->setV(k, adjl[vk - 1]);
		}
	}

	for (int i = 1; i <= n; i++) {
		adjl[0]->print(i);
	}

	delete[] adjl;
	return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;
typedef long long ll;
#define int ll

int g[105][105], d[105], n;

void bfs() {
  queue<int> q;
  q.push(0);
  fill(d, d + n, -1);
  d[0] = 0; 

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

signed main(void) {
  int u, k, v;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> u >> k;
    for (int j = 0; j < k; j++) {
      cin >> v;
      g[u-1][v-1] = 1;
    }
  }

  bfs();
  for (int i = 0; i < n; i++) {
    cout << i+1 << " " << d[i] << endl;
  }
  return 0;
}