local mce, mfl, msq, mmi, mma, mab = math.ceil, math.floor, math.sqrt, math.min, math.max, math.abs

local ffi = require("ffi")
local C = ffi.C
ffi.cdef[[
long long atoll(const char*);
]]

local function lltonumber(str)
  return C.atoll(str)
end

local function getprimes(x)
  local primes = {}
  local allnums = {}
  for i = 1, x do allnums[i] = true end
  for i = 2, x do
    if allnums[i] then
      table.insert(primes, i)
      local lim = mfl(x / i)
      for j = 2, lim do
        allnums[j * i] = false
      end
    end
  end
  return primes
end
local primes = getprimes(1000000)


local function getdivisorparts(x)
  local prime_num = #primes
  local tmp = {}
  local lim = mce(msq(x))
  local primepos = 1
  local dv = primes[primepos]
  while primepos <= prime_num and dv <= lim do
    if x % dv == 0 then
      local cnt = 1
      x = mfl(x / dv)
      while x % dv == 0 do
        x = mfl(x / dv)
        cnt = cnt + 1
      end
      tmp[dv] = cnt
      lim = mce(msq(x))
    end
    if primepos == prime_num then break end
    primepos = primepos + 1
    dv = primes[primepos]
  end
  if x ~= 1 then
    tmp[x] = 1
  end
  return tmp
end

local x, a, y, b = io.read():match("(%d+) (%d+) (%d+) (%d+)")
local function ans(f) print(f and "Yes" or "No") os.exit() end
x = tonumber(x)
y = tonumber(y)
a = lltonumber(a)
b = lltonumber(b)

local xdv = getdivisorparts(x)
local ydv = getdivisorparts(y)

for k, v in pairs(xdv) do
  xdv[k] = b * v
end
for k, v in pairs(ydv) do
  if not xdv[k] then ans(false) end
  if xdv[k] < a * v then ans(false) end
end
ans(true)