Go: package main

import (
	"fmt"
)

func main() {
	var n int
	fmt.Scan(&n)

	g := make([][]int, n+1)
	d := make([]int, n+1)
	for i := 0; i < n; i++ {
		var u,k int
		fmt.Scan(&u)
		fmt.Scan(&k)
		g[u] = make([]int, k)
		for j := 0; j < k; j++ {
			fmt.Scan(&g[u][j])
		}

		d[i+1] = -1
	}

	q := [][]int{}
	q = append(q, []int{1, 0})
	for len(q) > 0 {
		pop := q[0]
		if len(q) > 1 {
			q = q[1:]
		} else {
			q = [][]int{}
		}
		if d[pop[0]] >= 0 {
			continue
		}
		d[pop[0]] = pop[1]

		for j := 0; j < len(g[pop[0]]); j++ {
			q = append(q, []int{g[pop[0]][j], pop[1]+1})
		}
	}

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

C++: #include <iostream>
#include <iomanip> // << fixed << setprecision(xxx)
#include <algorithm> // do { } while ( next_permutation(A, A+xxx) ) ;
#include <vector>
#include <string> // to_string(nnn) // substr(m, n) // stoi(nnn)
#include <complex>
#include <tuple> // get<n>(xxx)
#include <queue>
#include <stack>
#include <map> // if (M.find(key) != M.end()) { }
#include <set> // S.insert(M);
// if (S.find(key) != S.end()) { }
// for (auto it=S.begin(); it != S.end(); it++) { }
// auto it = S.lower_bound(M);
#include <random> // random_device rd; mt19937 mt(rd());
#include <cctype>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib> // atoi(xxx)
using namespace std;

#define DEBUG 0 // change 0 -> 1 if we need debug.
// insert #if<tab> by my emacs. #if DEBUG == 1 ... #end

typedef long long ll;

// const int dx[4] = {1, 0, -1, 0};
// const int dy[4] = {0, 1, 0, -1};

// const int C = 1e6+10;
// const ll M = 1000000007;

class Edge {
public:
  int src, dst, cost;
  Edge(int s, int d, int c)
    : src(s), dst(d), cost(c) {}
  friend bool operator<(const Edge& x, const Edge& y) {
    return x.cost < y.cost;
  }
};

typedef Edge State;

class Graph {
public:
  int N;
  vector<Edge>* V;
  // dfs, bfs
  int* visited;
  int* from;
  int time;
  int* time_d;
  int* time_f; // dfs
  int* dist;

  Graph(int n)
    : N(n), time(0) {
    V = new vector<Edge>[N];
    from = new int[N];
    time_d = new int[N];
    time_f = new int[N];
    visited = new int[N];
    fill(visited, visited+N, 0);
    dist = new int[N];
  }
  ~Graph() {
    delete[] V;
    delete[] from;
    delete[] time_d;
    delete[] time_f;
    delete[] visited;
    delete[] dist;
  }

  void add_edge(int src, int dst, int cost = 1) {
    V[src].push_back(Edge(src, dst, cost));
  }

  void dfs(int start) {
    stack<State> S;
    S.push(State(-1, start, 0));
    while (!S.empty()) {
      State s = S.top();
      S.pop();
      if (visited[s.dst] == 0) {
        visited[s.dst] = 1;
        time_d[s.dst] = time++;
        from[s.dst] = s.src;
        dist[s.dst] = s.cost;
        S.push(s);
        for (auto x : V[s.dst]) {
          if (visited[x.dst] == 0) {
            S.push(State(s.dst, x.dst, s.cost + x.cost));
          }
        }
      } else if (visited[s.dst] == 1) {
        visited[s.dst] = 2;
        time_f[s.dst] = time++;
      }
    }
  }

  void bfs(vector<int> start) {
    queue<State> Q;
    for (auto x : start) {
      Q.push(State(-1, x, 0));
    }
    while (!Q.empty()) {
      State s = Q.front();
      Q.pop();
      if (visited[s.dst] == 0) {
        visited[s.dst] = 1;
        time_d[s.dst] = time++;
        from[s.dst] = s.src;
        dist[s.dst] = s.cost;
        for (auto x : V[s.dst]) {
          if (visited[x.dst] == 0) {
            Q.push(State(s.dst, x.dst, s.cost + x.cost));
          }
        }
      }
    }
  }  
};

int main () {
  int n;
  cin >> n;
  Graph graph(n);
  for (auto i = 0; i < graph.N; ++i) {
    int u, k;
    cin >> u >> k;
    --u;
    for (auto j = 0; j < k; ++j) {
      int v;
      cin >> v;
      --v;
      graph.add_edge(u, v);
    }
  }
  graph.bfs({0});
  for (auto i = 0; i < graph.N; ++i) {
    cout << i+1 << " ";
    if (graph.visited[i] == 0) {
      cout << -1 << endl;
    } else {
      cout << graph.dist[i] << endl;
    }
  }
}

C++: #include <map>
#include <set>
#include <list>
#include <cmath>
#include <deque>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <utility>
#include <iostream>
#include <algorithm>
#include <functional>
#include <unordered_map>
#include <unordered_set>

using namespace std;

#define ll long long
#define ull unsigned long long
#define INF (1 << 30)
#define LLINF (1LL << 62)
#define MOD7 1000000007
#define MOD9 1000000009
#define eps 1e-9
#define P pair<int, int>
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pul pair<ull, ull>
#define all(a) (a).begin(), (a).end()
#define FOR(i,a,b) for (int i=(a);i<(b);++i)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);--i)
#define REP(i,n) for (int i=0;i<(n);++i)
#define RREP(i,n) for (int i=(n)-1;i>=0;--i)

void YES() { cout << "YES" << endl; }
void NO() { cout << "NO" << endl; }
void Yes() { cout << "Yes" << endl; }
void No() { cout << "No" << endl; }
void yes() { cout << "yes" << endl; }
void no() { cout << "no" << endl; }

template<class T>
class DirectedGraph {
public:
	class Edge {
	public:
		int to;
		T cost;

		Edge(int t, T c) : to(t), cost(c) {}

		bool operator<(const Edge& right) const {
			return cost == right.cost ? to < right.to : cost < right.cost;
		}
	};

	vector<vector<Edge>> G;
	int V;

	DirectedGraph(int n = 0) {
		resize(n);
	}

	void resize(int n) {
		V = n;
		G.resize(n);
	}

	void addEdge(int from, int to, T cost = 0) {
		int v = max(from, to);
		if (v >= V)
			resize(v + 1);
		G[from].push_back(Edge(to, cost));
	}

	void dfs(int s) {
		vector<bool> visit(V);
		calcDfs(visit, s);
	}

	void calcDfs(vector<bool>& visit, int s) {
		if (visit[s])
			return;

		visit[s] = true;
		for (int i = 0; i < G[s].size(); ++i) {
			calcDfs(G[s][i].to);
		}
	}

	vector<int> bfs(int s) {
		vector<int> dist(V);
		queue<int> que;

		fill(dist.begin(), dist.end(), -1);
		dist[s] = 0;
		que.push(s);
		while (!que.empty()) {
			int from = que.front();
			que.pop();
			for (int i = 0; i < G[from].size(); ++i) {
				int to = G[from][i].to;
				if (dist[to] != -1)
					continue;
				dist[to] = dist[from] + 1;
				que.push(to);
			}
		}

		return dist;
	}
};

int main() {
	DirectedGraph<int> g;
	int n, from, k, to;
	cin >> n;
	for (int i = 0; i < n; ++i) {
		cin >> from >> k;
		while (k--) {
			cin >> to;
			g.addEdge(from, to);
		}
	}

	auto v = g.bfs(1);
	for (int i = 1; i <= n; ++i) {
		cout << i << " " << v[i] << endl;
	}

	return 0;
}

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

const long N = 100;
const long INFTY = (1<<21);

long n, M[N + 1][N + 1];
long d[N + 1];

void bfs(long s){
	queue<long> q;
	q.push(s);
	for (long i = 1; i <= n; i++) d[i] = INFTY;
	d[s] = 0;
	long u;
	while (!q.empty()){
		u = q.front();
		q.pop();
		for (long v = 1; v <= n; v++){
			if (M[u][v] == 0) continue;
			if (d[v] != INFTY) continue;
			d[v] = d[u] + 1;
			q.push(v);
		}
	}
	for (long i = 1; i <= n; i++){
		cout << i << " " << ((d[i] == INFTY) ? (-1) : d[i]) << endl;
	}
}

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

	bfs(1);

	return 0;
}