class Adjmat
  
  def initialize(n=0, inf=9876543210)
    @n = n
    @inf = inf
    @mat = Array.new(n){ Array.new(n, inf ) }.each_with_index{|s,i| s[i] = 0 }
  end
  
  def <= ( mat )
    @mat = mat
  end
  
  def add_edge(s,t,d=1)
    @mat[s][t] = d
    @mat[t][s] = d
  end
  
  def add_directed_edge(s,t,d=1)
    @mat[s][t] = d
  end
  
  def floyd_warshall!
    @n.times do |k|
      @n.times do |i|
        @n.times do |j|
          l = @mat[i][k]
          r = @mat[k][j]
          next if l == @inf || r == @inf
          nd = l + r
          @mat[i][j] = nd if @mat[i][j] > nd
        end
      end
    end
    @mat
  end
  
  def floyd_warshall
    res = @mat
    @n.times do |k|
      @n.times do |i|
        @n.times do |j|
          l = res[i][k]
          r = res[k][j]
          next if l == @inf || r == @inf
          res[i][j] = l + r if res[i][j] > l + r
        end
      end
    end
    res
  end
  
  def teleportation!(l)
    @n.times do |i|
      @n.times do |j|
        d = @mat[i][j]
        if 1 <= d && d <= l
          @mat[i][j] = 1
        else
          @mat[i][j] = @inf
        end
      end
    end
  end
  
  def teleportation(l)
    res = @mat
    @n.times do |i|
      @n.times do |j|
        d = res[i][j]
        if 1 <= d && d <= l
          res[i][j] = 1
        else
          res[i][j] = @inf
        end
      end
    end
  end
  
  def negative_cycle?
    @n.times{ |i| return true if @mat[i][i] < 0}
    false
  end
  
  def out
    @n.times do |i|
      @n.times do |j|
        print @mat[i][j] == @inf ? "INF" : @mat[i][j]
        print j != @n-1 ? " " : "\n"
      end
    end
  end
  
  def cost(s,t)
    @mat[s][t]
  end
  
  def inf
    @inf
  end
end

n, m, l = gets.to_s.split.map{|t| t.to_i }

a = Adjmat.new(n)

m.times do
  s,t,c = gets.to_s.split.map{|t| t.to_i }
  a.add_edge(s-1,t-1,c)
end

if m == 0
 q = gets.to_s.to_i
 q.times { puts -1 }
 exit
end

a.floyd_warshall!
a.teleportation!(l)
a.floyd_warshall!

if a.negative_cycle?
  puts "NEGATIVE CYCLE"
  exit
end

q = gets.to_s.to_i
q.times do
  s, t = gets.to_s.split.map{|t| t.to_i }
  puts a.cost(s-1,t-1) == a.inf ? -1 : a.cost(s-1,t-1) - 1
end
