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

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