Go: package main

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

type Queue []int

func (q *Queue) push(v int) {
	*q = append(*q, v)
}

func (q *Queue) pop() int {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	nVerts := scanInt(sc)
	graph := make([][]int, nVerts+1)

	for i := 0; i < nVerts; i++ {
		u := scanInt(sc)
		nDegrees := scanInt(sc)

		graph[u] = make([]int, nDegrees)
		for d := 0; d < nDegrees; d++ {
			graph[u][d] = scanInt(sc)
		}
	}

	paths := make([]int, nVerts+1)

	queue := Queue(make([]int, 0))
	queue.push(1)

	paths[1] = 1
	d := 2
	for len(queue) > 0 {
		u := queue.pop()

		pushed := false
		for _, v := range graph[u] {
			if paths[v] == 0 {
				paths[v] = d
				queue.push(v)
				pushed = true
			}
		}
		if pushed {
			d += 1
		}
	}

	w := bufio.NewWriter(os.Stdout)
	for i := 1; i <= nVerts; i++ {
		fmt.Fprintf(w, "%d %d\n", i, paths[i]-1)
	}
	w.Flush()
}

func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

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

using namespace std;
using P = pair<int, int>;

const int MAX = 101;

vector<int> G[MAX];
int d[MAX];

int main() {

    int n;
    cin >> n;

    fill(d, d + MAX, -1);

    for (int i = 0; i < n; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int v;
            cin >> v;
            G[u].push_back(v);
        }
    }

    queue<P> que;

    d[1] = 0;
    que.emplace(make_pair(1, d[1]));

    while (!que.empty()) {

        P &u = que.front();
        que.pop();

        for (auto v : G[u.first]) {
            if (d[v] == -1) {
                d[v] = u.second + 1;
                que.emplace(make_pair(v, d[v]));
            }
        }
    }

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

C++: #include<bits/stdc++.h>
using namespace std;
using ll = long long;
using Graph = vector<vector<int>>;
#define ALL(x) (x).begin(), (x).end()
#define REP(i ,n) for(int i = 0; i < (int)(n); i++)
#define pb push_back
typedef vector<int>vint;
typedef vector<ll>vll;
template<typename T> istream &operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template<typename A,typename B>inline void chmin(A &a,B b){if(a>b)a=b;}
template<typename A,typename B>inline void chmax(A &a,B b){if(a<b)a=b;}

int main()
{
    int N;
    cin >> N;
    Graph G(N);
    vint dist(N,-1);
    queue<int> que;

    REP(i,N){
        int u,k,v;
        cin >> u >> k;
        u--;
        REP(j,k){
            cin >> v;
            v--;
            G[u].pb(v);
        }
    }

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

    while(!que.empty()){
        int v = que.front();
        que.pop();

        for(auto nv:G[v]){
            if(dist[nv] != -1)continue;
            dist[nv] = dist[v]+1;
            que.push(nv);
        }
    }

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


}

C++: #include <iostream>
#include <queue> 
using namespace std;
int G[100][100];
int d[100];
int color[100];
int n;
queue<int> qu;
void bfs ()
{
    color[0] = 1;
    d[0] = 0;
    qu.push(0);
    while (!qu.empty())
    { 
        int u = qu.front(); qu.pop();
        for (int i = 0; i < n; i++)
        {
            if (G[u][i] == 1 && color[i] == 0)
            {
                color[i] = 1;
                d[i] = d[u] + 1;
                qu.push(i);
            }
        }
        color[u] = 2;
    } 
    return;
}

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

    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;
        } 
    }

    for (int i = 0; i < n; i++)
    {
        d[i] = -1; 
        color[i] = 0;
    } 
    bfs();
    for (int i = 0; i < n; i++)
    {
         printf("%d %d\n", i+1, d[i]);
    } 
    return 0;
}

C++: #include <iostream>
#include <queue>
using namespace std;

int main() {
	int a[101][101] = {{0}};
	int u, k, v, km;
	km = 0;
	while ( cin >> u, k ) {
		for ( int i = 1; i <= k; i++ ) {
			cin >> v;
			a[u][v] = 1;
		}
		km++;
	}
	int n0;
	int b[101] = {- 1};
	queue<int> q;
	q.push( 1 );
	b[1] = 0;
	for ( int i = 1; i <= km; i++ ) {
		n0 = q.front();
		q.pop();
		for ( int j = 1; j <= km + 1; j++ ) {
			if ( a[n0][j] == 1 && b[j] == - 1 ) {
				q.push( j );
				b[j] = b[n0] + 1;
			}
			if ( q.empty() ) break;
		}
	}
	for ( int i = 1; i <= km; i++ )
		cout << i << " " << b[i] << endl;
}

C++: #include <bits/stdc++.h>
using namespace std;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define vv(type, c, m, n, i) vector<vector<type>> c(m, vector<type>(n, i));
#define rep(i,a,n) for(int i=(a), i##_len=(n); i<i##_len; ++i)
#define rrep(i,a,n) for(int i=(a), i##_len=(n); i>i##_len; --i)
#define len(x) ((int)(x).size())
#define mp make_pair
#define eb emplace_back
typedef long long ll;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long long> vll;
typedef vector<string> vs;
typedef vector<bool> vb;
constexpr int MAX = 101;
constexpr int INFTY = (1<<21);
int n;
vv(int, M, MAX, MAX, 0);
vi d(MAX, INFTY);
inline void bfs(int s) {
	deque<int> dq;
	dq.eb(s);
	d[s] = 0;
	int u;
	while(!dq.empty()) {
		u = dq.front(); dq.pop_front();
		rep(v, 0, n) {
			if(M[u][v] == 0 || d[v] != INFTY) continue;
			d[v] = d[u] + 1;
			dq.eb(v);
		}
	}
	rep(i, 0, n) {
		cout << i + 1 << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl;
	}
}
int main() {
	cin >> n;
	int u, k, v;
	rep(i, 0, n) {
		cin >> u >> k;
		--u;
		rep(j, 0, k) {
			cin >> v;
			M[u][--v] = 1;
		}
	}
	bfs(0);
	return 0;
}