def inpf() a=gets.chomp.split(" ").map(&:to_f)end

def inps() a=gets.chomp.split(" ")end

def copy(a) Marshal.load(Marshal.dump(a)) end

def kaijo(n,r = 10**9+7)(n < 2)? 1 : (2..n).inject{|memo,u|memo=(memo*u)%r} end

def na(n,d=0) Array.new(n,d)end

def na2(n,m,d=0) Array.new(n){Array.new(m,d)}end

def na3(n,m,l,d=0) Array.new(n){Array.new(m){Array.new(l,d)}}end

def inp() a=gets.chomp.split(" ").map(&:to_i)end

def r_up(a, b) (a+b-1)/b end

def r_sort(a) a.sort{|a,b|b<=>a}; return a end

n = inp[0]
ga = inp
gb = inp
rt = []
(3).times do |i|
  rt[i] = [ga[i] * gb[i],i]
end
mt = []
(3).times do |i|
  mt[i] = [ga[i],gb[i]].min
end
ans = 0
r_sort(rt).each do |a|
  c = n / mt[a[1]]
  ans += c * a[0]
  n %= mt[a[1]]
end
p ans