local l, r, m, k = io.read("*n", "*n", "*n", "*n")
if l % m == 0 then
  print("Yes")
  os.exit()
end

l = 1LL * l
r = 1LL * r
m = 1LL * m
k = 1LL * k

if r / m ~= l / m then
  print("Yes")
  os.exit()
end

if (l * k) % m == 0 then
  print("Yes")
elseif (l * k) / m ~= (r * k) / m then
  print("Yes")
else
  print("No")
end