Go: package main

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

func main() {
	scn := bufio.NewScanner(os.Stdin)
	scn.Split(bufio.ScanWords)
	nextInt := func() int { scn.Scan(); r, _ := strconv.Atoi(scn.Text()); return r }
	w := bufio.NewWriter(os.Stdout)

	n := nextInt()
	vecs := make([][]int, n)
	for i := 0; i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			vecs[u-1] = append(vecs[u-1], nextInt()-1)
		}
	}

	ds := make([]int, 0, n)
	for i := 0; i < n; i++ {
		ds = append(ds, -1)
	}

	q := make([]int, 0, n)
	q = append(q, 0)
	ds[0] = 0

	for len(q) > 0 {
		i := pop(&q)
		for _, v := range vecs[i] {
			if ds[v] == -1 {
				ds[v] = ds[i]+1
				q = append(q, v)
			}
		}
	}

	for i, d := range ds {
		fmt.Fprintln(w, i+1, d)
	}

	w.Flush()
}

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

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[u] != 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<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;
  int i,j;

  cin >> n;
  for(i=0;i < n;i++)
    {
      for(j=0;j < n;j++)
        {
          M[i][j] = 0;
        }
    }

  for(i=0;i < n;i++)
    {
      cin >> u >> k;
      u--;
      for(j=0;j < k;j++)
        {
          cin >> v;
          v--;
          M[u][v] = 1;
        }
    }

  bfs(0);

  return 0;

}

C++: #include <iostream>
#include <vector>
#include <cmath>
#include <string>
#include <algorithm>
#include <iomanip>
#include <map>
#include <bitset>
#include <cstdio>
#include <set>
#include <stack>
#include <queue>
#include <cassert>
#include <numeric>
using namespace std;
typedef long long ll;
#define FOR(i,a,b) for (ll i=(a),__last_##i=(b);i<__last_##i;i++)
#define RFOR(i,a,b) for (ll i=(b)-1,__last_##i=(a);i>=__last_##i;i--)
#define REP(i,n) FOR(i,0,n)
#define RREP(i,n) RFOR(i,0,n)
#define __GET_MACRO3(_1, _2, _3, NAME, ...) NAME
#define rep(...) __GET_MACRO3(__VA_ARGS__, FOR, REP)(__VA_ARGS__)
#define rrep(...) __GET_MACRO3(__VA_ARGS__, RFOR, RREP)(__VA_ARGS__)
template<typename T> istream &operator>>(istream &is, vector<T> &v){ for (auto &x : v) is >> x; return is; }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& v) {
    REP(i,v.size()){if(i)os<<" ";os<<v[i];}return os;}
template<typename T> ostream& operator<<(ostream& os, const vector<vector<T>>& v) {
    REP(i,v.size()){if(i)os<<endl;os<<v[i];}return os;}
#define vi vector<int>
#define vii vector<vector<int>>
#define mii map<int,int>
#define Sort(v) sort(v.begin(),v.end())
#define Reverse(v) reverse(v.begin(),v.end())
#define ALL(a)  (a).begin(),(a).end()
#define pb push_back
#define mp make_pair
//#define int ll

const int md = 1000000007;
const int INF = 1<<30;



int main(){
    int n; cin >> n;
    vector<vector<int>> e(n);


    rep(i,n){
        int s; cin >> s;
        int tmp; cin >> tmp;
        rep(j,tmp){
            int to; cin >> to;
            e[i].push_back(to-1);
        }
    }

    vi ans(n,-1);
    rep(i,n){
        //if(i != 3) continue;
        queue<pair<int,int>> bfs;
        bfs.emplace(0,0);
        vector<bool> visit(n,false);
        while(!bfs.empty()){
            auto tmp = bfs.front();
            if(tmp.first == i) {
                ans[i] = tmp.second;
                break;
            }
            visit[tmp.first] = true;
            bfs.pop();

            rep(j,e[tmp.first].size()){
                if(!visit[e[tmp.first][j]]) {
                    //cout << j << endl;
                    bfs.emplace(e[tmp.first][j],tmp.second+1);
                }
            }
        }

    }

    rep(i,n){
        cout << i+1 << " " << ans[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 argc, char const *argv[])
{
    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 <iostream>
#include <cstdio>
using namespace std;

const int INF = 100000000;
int n, G[101][101];

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

    for (int i = 0; i < n; i++)
        printf("%d %d\n", i + 1, (G[0][i] < INF ? G[0][i] : -1));

    return 0;
}