func main()
	var A: int :: cui@inputInt()
	var B: int :: cui@inputInt()
	var a: int :: cui@inputInt()
	var b: int :: cui@inputInt()
	
	for x(0, 9000000)
		if(x % A = a & x % B = b)
			var ans: int :: x
			do cui@print("\{ans}\n")
			break x
		end if
	end for
end func