n, s, b = io.read("*n", "*n", "*n")
a = {}
for i = 1, n do
  a[i] = io.read("*n")
end
for i = 1, n - 1 do
  if s * b < a[i + 1] - a[i] then
    print("No") os.exit()
  end
end
print("Yes")