package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	in := bufio.NewReaderSize(os.Stdin, 1<<20)

	var n int
	fmt.Fscan(in, &n)

	a1 := make([]int, n-1)
	a2 := make([]int, n-1)
	b := make([]int, n)

	for i := 0; i < n-1; i++ {
		fmt.Fscan(in, &a1[i])
	}
	for i := 0; i < n-1; i++ {
		fmt.Fscan(in, &a2[i])
	}
	for i := 0; i < n; i++ {
		fmt.Fscan(in, &b[i])
	}

	pre1 := make([]int, n)
	for i := 1; i < n; i++ {
		pre1[i] = pre1[i-1] + a1[i-1]
	}

	suf2 := make([]int, n)
	for i := n - 2; i >= 0; i-- {
		suf2[i] = suf2[i+1] + a2[i]
	}

	const inf = int(1e9)
	min1, min2 := inf, inf

	for i := 0; i < n; i++ {
		cost := pre1[i] + b[i] + suf2[i]
		if cost < min1 {
			min2 = min1
			min1 = cost
		} else if cost < min2 {
			min2 = cost
		}
	}

	fmt.Println(min1 + min2)
}