func main()
	var a: int :: cui@inputInt()
	var b: int :: cui@inputInt()
	var c: int :: cui@inputInt()
	var d: int :: cui@inputInt()
	var e: int :: cui@inputInt()
	var n: int :: b - c
	var ans: int :: 0
	var x: int :: d
	for i(1, n)
		if(i % 10 = 0 & e <= x)
			do x :- e
		end if
		do ans :+ x
	end for
	do cui@print("\{ans}\n")
end func