# Node
class Node
  attr_accessor :id, :edges, :cost, :done

  def initialize(id, edges = [], cost = nil, done = false)
    @id, @edges, @cost, @done = id, edges, cost, done
  end
end

# Edge
class Edge
  attr_accessor :to, :cost

  def initialize(to, cost)
    @to, @cost = to, cost
  end
end

# Dijkstra
class Dijkstra
  attr_accessor :nodes

  def initialize(data)
    @nodes = {}
    data.each do |id, edges|
      edges.map! { |edge| Edge.new(*edge) }
      @nodes[id] = Node.new(id, edges)
    end
  end

  def start(start_id)
    @nodes.each do |id, node|
      node.done = false
      node.cost = node.id == start_id ? 0 : -1
    end

    loop do
      done_node = nil
      @nodes.each do |id, node|
        next if node.done || node.cost < 0
        done_node = node if done_node.nil? || node.cost < done_node.cost
      end
      break if done_node.nil?
      done_node.done = true
      done_node.edges.each do |edge|
        node = @nodes[edge.to]
        cost = done_node.cost + edge.cost
        node.cost = cost if node.cost < 0 || cost < node.cost
      end
    end
  end
end

n = gets.chop.to_i

data = {}

n.times do
  u, k, *edges = gets.split.map(&:to_i)
  data[u] = edges.each_slice(2).to_a
end

d = Dijkstra.new data
d.start(0)
d.nodes.each do |id, node|
  puts "#{id} #{node.cost}"
end