class UnionFind
  def initialize(n)
    @size = Array.new(n, 1)
    @rank = Array.new(n, 0)
    @parent = []

    (0..n).each do |i|
      @parent[i] = i
    end
  end

  def find(x)
    if @parent[x] == x
      x
    else
      @parent[x] = find(@parent[x])
    end
  end

  def unite(x, y)
    x = find(x)
    y = find(y)
    return if x == y

    if @rank[x] < @rank[y]
      @parent[x] = y
      @size[y] += @size[x]
    else
      @parent[y] = x
      @size[x] += @size[y]

      @rank[x] += 1 if @rank[x] == @rank[y]
    end
  end

  def same?(x, y)
    find(x) == find(y)
  end

  def size(x)
    @size[find(x)]
  end
end

N, D, T = gets.split.map(&:to_i)
X = gets.split.map(&:to_i)

uf = UnionFind.new(N)

0.upto(N - 2) do |i|
  (i + 1).upto(N - 1) do |j|
    dist = (X[i] - X[j]).abs

    if dist % D == 0 && dist / D <= T
      uf.unite(i, j)
    end
  end
end

pairs = Hash.new { |h, k| h[k] = [] }
N.times do |i|
  pa = uf.find(i)
  pairs[pa] << i
end

ans = 0

pairs.each do |_, ids|
  min, max = ids.map { |id| X[id] }.minmax

  cnt = ((max + T * D) - (min - T * D)) / D + 1
  ans += cnt
end

puts ans