We have a 2 \times N grid. We will denote the square at the i-th row and j-th column (1 \leq i \leq 2, 1 \leq j \leq N) as (i, j).  You are initially in the top-left square, (1, 1). You will travel to the bottom-right square, (2, N), by repeatedly moving right or down.  The square (i, j) contains A_{i, j} candies. You will collect all the candies you visit during the travel. The top-left and bottom-right squares also contain candies, and you will also collect them.  At most how many candies can you collect when you choose the best way to travel?
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))

maxans=0
for i in range(n):
  ans=sum(a[0:i+1]+b[i:n])
  maxans=max(ans,maxans)
  print(ans)
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))

maxans=0
for i in range(n):
  ans=sum(a[0:i+1]+b[i:n])
  maxans=max(ans,maxans)
print(maxans)
