N = int(input())
A = [list(map(int, input().split()))+[0] for _ in range(3)]

inf = float('inf')

# dp[i][j][k] := i個目まで決めて、直前の状態がj、移動回数がkのときの最大値
dp = [[[-inf]*5 for _ in range(3)] for _ in range(N+2)]
dp[0][0][0] = 0

for i in range(N+1):
    for j in range(3):
        for k in range(5):
            for nj in range(3):
                nk = k + abs(j-nj)
                if nk < 5:
                    dp[i+1][nj][nk] = max(dp[i+1][nj][nk], dp[i][j][k] + A[nj][i])

ans = 0
for k in range(5):
    ans = max(ans, dp[N+1][0][k])

print(ans)