(function() {

  const input = `1 2
  1 3
  2 4
  3 5
  1 5
  1`;


  const makeNode = number => ({number, nodes: [], checked: false});
  const refsByNumber = {};
  const getNode = number => refsByNumber[number] || makeNode(number);

  const getResult = companyNumber => {
    const root = getNode(companyNumber);
    root.checked = true;
    const stack = root.nodes;
    const result = [];
    let c;
    do {
      c = 0;
      const batch = [];
      for (let i = 0; i < stack.length; i++) {
        const node = stack.shift();
        if (!node.checked) {
          batch.push(node.number);
          node.checked = true;
        }
        node.nodes.forEach(n => {
          if (!n.checked) {
            stack.push(n);
          }
        });
        c += node.nodes.length;
      }
      if (batch.length > 0) {
        result.push(batch);
      }
    } while (c > 0);
    return result;
  }

  const lines = input.split("\n");
  lines.forEach(line => {
    const parts = line.split(" ");
    if (parts.length === 2) {
      const node1 = getNode(Number(parts[0]));
      const node2 = getNode(Number(parts[1]));

      node1.nodes.push(node2);
      node2.nodes.push(node1);

      refsByNumber[node1.number] = node1;
      refsByNumber[node2.number] = node2;
    } else if (parts.length === 1) {
      console.log(refsByNumber);
      console.log(getResult(Number(parts[0])));
    }
  });

}())

function solve(citiesCount, fromCities, toCities, companyCity) {
  const result = new Set();
  result.add(companyCity);

  const roads = toRoads(fromCities, toCities);

  let neighbours = findCityNeighbours(companyCity, roads);
  while (true) {
    const oldSize = result.size;
    neighbours.sort(numbersComparator).forEach((city) => result.add(city));

    if (oldSize === result.size) break;

    neighbours = neighbours.map((neighbour) => findCityNeighbours(neighbour, roads)).flat();
  }

  return [...result].slice(1);
}

function toRoads(fromCities, toCities) {
  const roads = [];

  for (let i = 0; i < fromCities.length; i++) {
    const from = fromCities[i];
    const to = toCities[i];

    roads.push([from, to]);
  }

  return roads;
}

function findCityNeighbours(city, roads) {
  const neighbours = [];

  roads.forEach((road) => {
    if (road[0] === city) {
      neighbours.push(road[1]);
    } else if (road[1] === city) {
      neighbours.push(road[0]);
    }
  });

  return neighbours;
}

function numbersComparator(num1, num2) {
  return num1 - num2;
}