func main()
	var a: []char :: cui@input()
	var b: []char :: cui@input()
	
	do a.reverse()
	do b.reverse()
	var ans: int :: 0
	var d: int :: 1
	for i(0, [^a, ^b].max())
		var x: int :: 0
		if(i < ^a)
			do x :+ a[i] $ int - '0' $ int
		end if
		if(i < ^b)
			do x :+ b[i] $ int - '0' $ int
		end if
		if(x = 1)
			do ans :+ d
		end if
		do d :* 2
	end for
	do cui@print("\{ans}\n")
end func