local n, c, k = io.read("*n", "*n", "*n")
local t = {}
for i = 1, n do
  t[i] = io.read("*n")
end
table.sort(t)
local ans = 0
local curnum, curtime = 0, -1000000007
for i = 1, n do
  if curnum == c or curtime + k < t[i] then
    ans = ans + 1
    curnum = 0
    curtime = t[i]
  end
  curnum = curnum + 1
end
print(ans)
