N = gets.to_i
A = Array.new(3)
B = Array.new(3)
(0..2).each do |i|
    A[i], B[i] = gets.split.map(&:to_i)
end
if A[1]*B[2] < A[2]*B[1] then
    A[2],B[2],A[1],B[1]=A[1],B[1],A[2],B[2]
end
if A[0]*B[2] < A[2]*B[0] then
    A[0],B[0],A[2],B[2]=A[2],B[2],A[0],B[0]	
end

ans=0
(0..A[2]).each do |i|
    (0..A[2]).each do |j|	
        ans = [ans, (N-A[0]*i-A[1]*j)/A[2]*B[2] + i*B[0]+j*B[1]].max if A[0]*i+A[1]*j <= N
    end
end
puts (ans)