Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	nodes := make([]Node, n)

	for i := 0; i < n; i++ {
		nodes[i].list = make([]int, 0)
		nodes[i].d = -1
	}

	for i := 0; i < n; i++ {
		u := getNextInt(scanner)
		k := getNextInt(scanner)
		u--
		for ii := 0; ii < k; ii++ {
			v := getNextInt(scanner)
			v--
			nodes[u].list = append(nodes[u].list, v)
		}
	}

	queue := make([]int, n)
	queue[0] = 0
	nodes[0].d = 0
	d := 0
	i, j := 0, 1
	for i < j {
		d++
		prev := j
		for i < prev {
			for k, l := 0, len(nodes[queue[i]].list); k < l && i < n; k++ {
				if nodes[nodes[queue[i]].list[k]].d != -1 {
					continue
				}
				nodes[nodes[queue[i]].list[k]].d = d
				queue[j] = nodes[queue[i]].list[k]
				j++
			}
			i++
		}
	}

	for i := 0; i < n; i++ {
		fmt.Fprintln(writer, fmt.Sprintf("%d %d", i+1, nodes[i].d))
	}

	writer.Flush()
}

// Node ...
type Node struct {
	list []int
	d    int
}

C++: #include <algorithm>
#include <iostream>
#include <vector>
#include <math.h>
#include <set>
#include <map>
#include <string>
#include <stack>
#include <queue>
#include <iomanip>
#include <numeric>
#include <tuple>
#define _USE_MATH_DEFINES
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> plglg;
typedef tuple<int, int, int> tiii;
typedef tuple<ll, ll, ll> tlglglg;
double pi = 3.141592653589793;
ll mod = 1000000007;
int intmax = 2147483647;
int intmin = -2147483648;
ll llmax = 9223372036854775807;
ll llmin = -9223372036854775807;

struct edge {
    int to, cost;
};

int V;
vector<int> G[1000000];
ll d[1000000];

void DFS(int n) {
    fill(d, d + V, llmax);
    queue<int> que;
    d[n] = 0;
    que.push(n);
    while (que.size() > 0) {
        int base = que.front();
        que.pop();
        int s = G[base].size();
        for (int i = 0; i < s; i++) {
            int to = G[base][i];
            if (d[to] == llmax) {
                d[to] = d[base] + 1;
                que.push(to);
            }
        }
    }
}

int main() {
    int N;
    cin >> N;
    V = N;
    for (int i = 0; i < N; i++) {
        int u, k;
        cin >> u >> k;
        for (int j = 0; j < k; j++) {
            int n;
            cin >> n;
            G[i].push_back(n - 1);
        }
    }
    DFS(0);
    for (int i = 0; i < N; i++) {
        if (d[i] == llmax) {
            d[i] = -1;
        }
        cout << i + 1 << " " << d[i] << endl;
    }
}

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

int n;
vector <int> G[101];
queue <int> Q;
int  d[100];
int  dis[101];


int visit(int x){
  int t,i;
  
  Q.push(x);
  dis[x] = 0;
  d[x] = 1;

  while(Q.empty() == false) {
    
    // cout << "start Q" <<endl;

    t = Q.front();
    Q.pop();

    for(i=0; i<G[t].size();i++) {
      if(d[G[t][i]] == 0 ) {
	d[G[t][i]] = 1;
	dis[G[t][i]] = dis[t] + 1;

	Q.push(G[t][i]);
      }

    }
  }
}
    
int main() {
  
  int i,j,k,l,u,a,t;
  
  
  scanf("%d",&n);

  
  
  for(i=0;i<n;i++){
    d[i] = 0;
    dis[i] = -1;
    scanf("%d %d ",&k,&u);
    
    for(j=0;j<u;j++) {
      scanf("%d",&a);
      G[k-1].push_back(a-1);
      // printf("G[%d][%d] = 1\n",i,k-1);
    }
  }
  
  
  visit(0);

  

  for(i=0;i<n;i++) cout << i+1<<" " << dis[i] <<endl;



  return 0;

    
    
}

C++: #include <iostream>
#include <vector>
#include <list>
#include <cstdlib>
#include <climits>

const int MAX_N = 100;

struct Node {
  int v;
  int d;
  bool visited;
};

int main(void) {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);  

  int n = 0;
  std::cin >> n;

  std::vector<std::vector<int> *> *graph = new std::vector<std::vector<int> *>(n + 1);
  std::vector<struct Node *> *nodes = new std::vector<struct Node *>(n + 1);
  
  for (int i = 1; i <= n; i++) {
    int v = 0;
    std::cin >> v;

    int k = 0;
    std::cin >> k;

    std::vector<int> *neighbors = new std::vector<int>(k);

    for (int i = 0; i < k; i++) {
      int a = 0;
      std::cin >> a;

      neighbors->at(i) = a;
    }

    graph->at(i) = neighbors;

    struct Node *node = (struct Node *) std::malloc(sizeof(struct Node));

    node->v = i;
    node->d = INT_MAX;
    node->visited = false;
    
    nodes->at(v) = node;
  }

  int count = 0;
  int start = 1;

  std::list<int> *stack = new std::list<int>();

  stack->push_back(nodes->at(start)->v);

  while (!stack->empty()) {
    std::vector<int> *newNodes = new std::vector<int>();

    while (!stack->empty()) {    
      int v = stack->front();
      stack->pop_front();

      if (node->at(v)->d < count) {
	nodes->at(v)->d = count;
      }
      
      nodes->at(v)->visited = true;
      
      std::vector<int> *neighbors = graph->at(v);

      for (std::vector<int>::iterator iterator = neighbors->begin(); iterator != neighbors->end(); ++iterator) {
	struct Node *node = nodes->at(*iterator);

	if (!node->visited) {
	  newNodes->push_back(node->v);
	}
      }
    }

    for (std::vector<int>::iterator iterator = newNodes->begin(); iterator != newNodes->end(); ++iterator) {
      stack->push_front(*iterator);
    }

    count++;
  }

  for (std::vector<struct Node *>::iterator iterator = nodes->begin() + 1; iterator != nodes->end(); ++iterator) {
    struct Node *node = *iterator;

    if (node->d == INT_MAX) {
      node->d = -1;
    }
        
    std::cout << node->v << " " << node->d << std::endl;
  }
  
  return 0;
}