Go: package main

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

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

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

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
type Queue struct {
	arr []int
}

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

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

func (q *Queue) isEmpty() bool {
	return len(q.arr) == 0
}

func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	N := sc.nextInt()
	G := make([][]int, N)
	for i := 0; i < N; i++ {
		u, k := sc.nextInt()-1, sc.nextInt()
		for j := 0; j < k; j++ {
			G[u] = append(G[u], sc.nextInt()-1)
		}
	}
	var q Queue
	seen := make([]int, N)
	for i := 0; i < N; i++ {
		seen[i] = -1
	}
	var search func(cur int)
	search = func(cur int) {
		for i := 0; i < len(G[cur]); i++ {
			next := G[cur][i]
			if seen[next] == -1 {
				q.push(next)
				seen[next] = seen[cur] + 1
			}
		}
	}
	q.push(0)
	seen[0] = 0
	for !q.isEmpty() {
		search(q.pop())
	}

	for i := 0; i < N; i++ {
		fmt.Fprintln(wtr, i+1, seen[i])
	}
	wtr.Flush()
}

C++: #include <iostream> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#define ll long long
#define ALL(x) (x).begin(),(x).end()
#define rep(i, n) for(int i = 0; i < (int)(n); i++)
#define vi vector<int>
#define vvi vector<vector<int>>
#define pii pair<int,int>
#define pint_int 2000000003
using namespace std;

class BFS {
public:
    vector<vector<int>> Graph_as_list;

    void emplace_back(vector<int> list) {
        Graph_as_list.push_back(list);
    }
    vector<int> Search(int u) {// search from node u
        vector<int> dist_from_u(Graph_as_list.size(), pint_int);
        queue<int> que;

        que.push(u);
        dist_from_u[u] = 0;
        while (!que.empty()) {
            int u = que.front(); que.pop();
            for (int next_node : Graph_as_list[u]) {
                if (dist_from_u[u] + 1 < dist_from_u[next_node]) {
                    dist_from_u[next_node] = dist_from_u[u] + 1;
                    que.push(next_node);
                }
            }
        }
        for (int& elem : dist_from_u) {
            if (elem == pint_int) elem = -1;
        }
        return dist_from_u;
    }
};

int main() {
    int n; cin >> n;
    BFS bfs;
    for (int i = 0; i < n; i++) {
        int u, k; cin >> u >> k; u--;
        vi temp;
        for (int j = 0; j < k; j++) {
            int v; cin >> v; v--;
            temp.push_back(v);
        }
        bfs.emplace_back(temp);
    }
    vi ans = bfs.Search(0);
    for (int i = 0; i < ans.size(); i++) {
        cout << i + 1 << " " << ans[i] << endl;
    }

}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
const ll INF = 1LL << 60;
const int MAX = 1000000010;
const ll MOD = 1000000007;
const double PI = acos(-1);

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

    queue<int> que;
    vector<int> dist(N, -1);
    dist[0] = 0;
    que.push(0);

    while (!que.empty()) {
        int u = que.front(); que.pop();
        
        for (auto nv : G[u]) {
            if (dist[nv] != -1) continue;

            dist[nv] = dist[u] + 1;
            que.push(nv);
        }
    }

    for (int i = 0; i < N; i++) {
        cout << i + 1 << " " << dist[i] << endl;
    }

    return 0;
}

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

int G[110][110];
int N,num,lines,tar;
int D[1000];
int ret[1000];

void bfs(int src);

int main() {
	for (int i=0;i<110;i++) {
		for(int j=0;j<110;j++) {
			G[i][j] = 0;
		}
	}
	for(int i=0;i<1000;i++) {
		D[i] = 100;
	}
	cin >> N;
	for(int i=0;i<N;i++) {
		cin >> num >> lines;
		for(int j=0;j<lines;j++) {
			cin >> tar;
			G[num][tar] = 1;
		}
	}
	/*
	for(int i=0;i<num+1;i++) {
		for(int j=0;j<num+1;j++) {
			cout << G[i][j] << " ";
		}
		cout << endl;
	}
	*/
	bfs(1);
	for(int i=1;i<num+1;i++) {
		if((ret[i] == 0) && (i>1)) ret[i] = -1;
		cout << i << " " << ret[i] << endl;
	}

}
void bfs(int src) {
	int cur,dst;
	//cerr << "bfs root = " << src << endl;
	queue<int> Q; // ??´??°????????????????????\????????????
	Q.push(src);
	D[src] = 0; // ?????????
	while (! Q.empty()) {
		int cur = Q.front(); // ??????????´????????????????
		Q.pop();
// ???????¢??????¨??¨???
		ret[cur] = D[cur];
		//cerr << cur << " " << D[cur] << endl;
		for (int dst=1;dst<N+1;dst++) { // ???????????? dst ????????????
			if ((G[cur][dst] == 1) && (D[dst] == 100)) { // cur ?????? dst ??????????????????dst ???????¨??????????
				D[dst] = D[cur]+1; //
				Q.push(dst); // dst ????¨???????????????????
			}
		}
	}
}