Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

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

	dim, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
		}
	}
}

func nextInt(sc *bufio.Scanner) (int, error) {
	sc.Scan()
	return strconv.Atoi(sc.Text())
}

C++: #include <bits/stdc++.h>

using namespace std;

using ll = long long;

ll MAX_N = 1e5;
vector<vector<ll> > graph(MAX_N);
vector<bool> visited(MAX_N);

// ALDS1_11_C
vector<ll> d(MAX_N);

// O(E)
void bfs(ll u){
    queue<pair<ll, ll> > Q; // v, dist
    visited[u] = true;
    Q.push(make_pair(u, 0));
    while(!Q.empty()){
        pair<ll, ll> p = Q.front(); Q.pop();
        ll u = p.first, dist = p.second;
        //
        d[u] = dist;
        for(ll v: graph[u]){
            if(!visited[v]){
                visited[v] = true;
                Q.push(make_pair(v, dist + 1));
            }
        }
    }
}

// ALDS1_11_C: verified
int main(){
    cin.tie(0);
    ios_base::sync_with_stdio(false);
    ll n; cin >> n;
    for(ll i=0;i<n;i++){
        ll u, k; cin >> u >> k;
        for(ll j=0;j<k;j++){
            ll v; cin >> v;
            graph[u - 1].push_back(v - 1);
        }
    }
    fill(d.begin(), d.end(), -1);
    bfs(0);
    for(ll i=0;i<n;i++) cout << i + 1 << " " << d[i] << endl;
}

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 <bits/stdc++.h>
using namespace std;

static const int N = 100;
static const unsigned int INF = (1 << 31);

int n,m[N][N];
int dist[N];

void bfs(int s){
    queue<int> q;
    q.push(s);
    for(int i=0;i<n;i++) dist[i] = INF;
    dist[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(dist[v] != INF) continue;
            dist[v] = dist[u]+1;
            q.push(v);
        }
    }
    for(int i=0;i<n;i++){
        cout << i+1 << ' ' << ((dist[i] == INF) ? -1 : dist[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);
}

C++: #include <bits/stdc++.h>
using ll = long long;
using namespace std;
#define _overload3(_1, _2, _3, name, ...) name
#define _rep(i, n) repi(i, 0, n)
#define repi(i, a, b) for(int i = int(a); i < int(b); ++i)
#define rep(...) _overload3(__VA_ARGS__, repi, _rep, )(__VA_ARGS__)
const long long INFLL = 1LL << 60;
const int INFINT = 1 << 30;
const long long MOD = 1e9 + 7;

vector<vector<int>> G(101, vector<int>(0));
vector<int> c(101, 0);
vector<int> d(101, 0);
vector<int> f(101, 0);

template <class T> void vecout(T V) {
    auto t = V.begin();
    *t++;
    while(t != V.end()) {
        cout << " " << *t++;
        // if(t != V.end()) cout << " ";
    }
    cout << endl;
};

int t = 0;
void dfs(int i) {
    if(c[i]) return;
    c[i] = 1;
    d[i] = ++t;
    for(auto e : G[i])
        dfs(e);
    f[i] = ++t;
}

class node {
  public:
    int dist = -1;
    vector<int> nex;
};

int main() {
    cin.tie(0);
    ios::sync_with_stdio(false);
    int n, u, k, a;
    cin >> n;
    vector<node> Node(n + 1);
    queue<int> Q;
    rep(i, n) {
        cin >> u >> k;
        rep(j, k) {
            cin >> a;
            Node.at(u).nex.push_back(a);
        }
    }
    Node[1].dist = 0;
    Q.push(1);

    while(!Q.empty()) {
        int v = Q.front();
        Q.pop();
        for(auto e : Node[v].nex) {
            if(Node[e].dist > -1) continue;
            Node[e].dist = Node[v].dist + 1;
            Q.push(e);
        }
    }

    rep(i, 1, n + 1) cout << i << " " << Node[i].dist << "\n";
}