import std.algorithm, std.array, std.container, std.range, std.bitmanip;
import std.numeric, std.math, std.bigint, std.random;
import std.string, std.conv, std.stdio, std.typecons;

struct range {
  long s;
  long e;
}

void main()
{
  auto rd = readln.split.map!(to!long);
  auto n = rd[0], d = rd[1], t = rd[2];
  auto xi = readln.split.map!(to!long).array;

  xi.sort();

  long[][long] aij;
  foreach (x; xi) {
    if (x % d == 0 || x >= 0)
      aij[x % d] ~= x / d;
    else
      aij[x % d + d] ~= x / d - 1;
  }
  auto bij = aij.values;

  auto cij = bij.map!((bi) {
    range[] di;
    foreach (b; bi) {
      auto e = range(b - t, b + t);
      if (di.empty || di.back.e < e.s)
        di ~= e;
      else
        di.back.e = e.e;
    }
    return di;
  }).array;

  auto r = cij.map!(ci => ci.map!(c => c.e - c.s + 1).sum).sum;

  writeln(r);
}