func main()
	var A: int :: cui@inputInt()
	var B: int :: cui@inputInt()
	var a: int :: cui@inputInt()
	var b: int :: cui@inputInt()
	
	var x: int :: 0
	while(true)
		if(x % A = a & x % B = b)
			var ans: int :: x
			do cui@print("\{ans}\n")
			ret
		end if
		do x :+ 1
	end while
end func