Dima liked the present he got from Inna very much. He liked the present he got from Seryozha even more. 

Dima felt so grateful to Inna about the present that he decided to buy her n hares. Inna was very happy. She lined up the hares in a row, numbered them from 1 to n from left to right and started feeding them with carrots. Inna was determined to feed each hare exactly once. But in what order should she feed them?

Inna noticed that each hare radiates joy when she feeds it. And the joy of the specific hare depends on whether Inna fed its adjacent hares before feeding it. Inna knows how much joy a hare radiates if it eats when either both of his adjacent hares are hungry, or one of the adjacent hares is full (that is, has been fed), or both of the adjacent hares are full. Please note that hares number 1 and n don't have a left and a right-adjacent hare correspondingly, so they can never have two full adjacent hares.

Help Inna maximize the total joy the hares radiate. :)

Input

The first line of the input contains integer n (1 ≤ n ≤ 3000) — the number of hares. Then three lines follow, each line has n integers. The first line contains integers a1 a2 ... an. The second line contains b1, b2, ..., bn. The third line contains c1, c2, ..., cn. The following limits are fulfilled: 0 ≤ ai, bi, ci ≤ 105.

Number ai in the first line shows the joy that hare number i gets if his adjacent hares are both hungry. Number bi in the second line shows the joy that hare number i radiates if he has exactly one full adjacent hare. Number сi in the third line shows the joy that hare number i radiates if both his adjacent hares are full.

Output

In a single line, print the maximum possible total joy of the hares Inna can get by feeding them.

Examples

Input

4
1 2 3 4
4 3 2 1
0 1 1 0


Output

13


Input

7
8 5 7 6 1 8 9
2 7 9 5 4 3 1
2 3 3 4 1 1 3


Output

44


Input

3
1 1 1
1 2 1
1 1 1


Output

4
import java.util.*;

public class Main {
	static long mod = 1000000007;
  static int size = 200000;
	static long[] fac = new long[size];
	static long[] finv = new long[size];
	static long[] inv = new long[size];
	static int INF = Integer.MAX_VALUE;
	//Dima and Hares
 	public static void main(String[] args){
		Scanner scanner = new Scanner(System.in);
		int n = scanner.nextInt();
		int[] a = new int[n+1];
		int[] b = new int[n+1];
		int[] c = new int[n+1];
		for(int i = 1; i <= n; i++){
			a[i] = scanner.nextInt(); //どっちもお腹空いてる
		}
		for(int i = 1; i <= n; i++){
			b[i] = scanner.nextInt(); //片方お腹空いてる
		}
		for(int i = 1; i <= n; i++){
			c[i] = scanner.nextInt(); //どっちもお腹いっぱい
		}
		if(n == 1){
			System.out.println(a[1]);
			return;
		}
		//dp[i][j]:= i番目までのうさぎに餌をあげる時、i+1番目のうさぎが
		//既にj:0 餌をもらっていない、j:1餌をもらっている時の満足度の合計の最大値
		int[][] dp = new int[n+1][2];
		for(int i = 1; i <= n; i++){
			dp[i][0] = 0;
			dp[i][1] = 0;
		}
		dp[1][0] = a[1];
		dp[1][1] = b[1];
		for(int i = 2; i < n; i++){
			dp[i][1] = Math.max(dp[i-1][0]+c[i],dp[i-1][1]+b[i]);
			dp[i][0] = Math.max(dp[i-1][0]+b[i],dp[i-1][1]+a[i]);
		}
		System.out.println(Math.max(dp[n-1][0]+b[n],dp[n-1][1]+a[n]));

	}
	public static boolean isPrime(int n){
		if(n == 1) return false;
		if(n == 2 || n == 3) return true;
		for(int i = 2; i <= Math.sqrt(n); i++){
			if(n % i == 0) return false;
		}
		return true;
	}
	// tar の方が数字が大きいかどうか
	static boolean compare(String tar, String src) {
		if (src == null) return true;
		if (src.length() == tar.length()) {
			int len = tar.length();
			for (int i = 0; i < len; i++) {
				if (src.charAt(i) > tar.charAt(i)) {
					return false;
				} else if (src.charAt(i) < tar.charAt(i)) {
					return true;
				}
			}
			return tar.compareTo(src) > 0 ? true : false;
		} else if (src.length() < tar.length()) {
			return true;
		} else if (src.length() > tar.length()) {
			return false;
		}
		return false;
	}
	public static class Edge{
		int from;
		int to;
		Edge(int from, int to){
			this.from = from;
			this.to = to;
		}
	}
	public static void swap(long a, long b){
		long tmp = 0;
		if(a > b){
			tmp = a;
			a = b;
			b = tmp;
		}
	}
  static class Pair implements Comparable<Pair>{
    int first, second;
    Pair(int a, int b){
        first = a;
        second = b;
    }
    @Override
    public boolean equals(Object o){
        if (this == o) return true;
        if (!(o instanceof Pair)) return false;
        Pair p = (Pair) o;
        return first == p.first && second == p.second;
    }
    @Override
    public int compareTo(Pair p){
        return first == p.first ? second - p.second : first - p.first; //firstで昇順にソート
        //return (first == p.first ? second - p.second : first - p.first) * -1; //firstで降順にソート
        //return second == p.second ? first - p.first : second - p.second;//secondで昇順にソート
        //return (second == p.second ? first - p.first : second - p.second)*-1;//secondで降順にソート
    }
  }

  //繰り返し二乗法
  public static long pow(long x, long n){
    long ans = 1;
    while(n > 0){
      if((n & 1) == 1){
        ans = ans * x;
        ans %= mod;
      }
      x = x * x % mod;
      n >>= 1;
    }
    return ans;
  }

	public static long div(long x, long y){
		return (x*pow(y, mod-2))%mod;
	}

  //fac, inv, finvテーブルの初期化、これ使う場合はinitComb()で初期化必要
	public static  void initComb(){
		fac[0] = finv[0] = inv[0] = fac[1] = finv[1] = inv[1] = 1;
		for (int i = 2; i < size; ++i) {
			fac[i] = fac[i - 1] * i % mod;
			inv[i] = mod - (mod / i) * inv[(int) (mod % i)] % mod;
			finv[i] = finv[i - 1] * inv[i] % mod;
		}
	}

	//nCk % mod
	public static long comb(int n, int k){
		return fac[n] * finv[k] % mod * finv[n - k] % mod;
	}

	//n! % mod
	public static long fact(int n){
		return fac[n];
	}

	//(n!)^-1 with % mod
	public static long finv(int n){
		return finv[n];
	}

  static class UnionFind {
    int[] parent;
    public UnionFind(int size) {
      parent = new int[size];
      Arrays.fill(parent, -1);
    }
    public boolean unite(int x, int y) {
      x = root(x);
      y = root(y);
      if (x != y) {
        if (parent[y] < parent[x]) {
          int tmp = y;
          y = x;
          x = tmp;
        }
        parent[x] += parent[y];
        parent[y] = x;
        return true;
      }
      return false;
    }
    public boolean same(int x, int y) {
      return root(x) == root(y);
    }
    public int root(int x) {
      return parent[x] < 0 ? x : (parent[x] = root(parent[x]));
    }
    public int size(int x) {
      return -parent[root(x)];
    }
  }
	public static int upperBound(int[] array, int value) {
			 int low = 0;
			 int high = array.length;
			 int mid;
			 while( low < high ) {
					 mid = ((high - low) >>> 1) + low; // (high + low) / 2
					 if( array[mid] <= value ) {
							 low = mid + 1;
					 } else {
							 high = mid;
					 }
			 }
			 return low;
	 }
	 public static final int lowerBound(final int[] arr, final int value) {
    	int low = 0;
    	int high = arr.length;
    	int mid;
    	while (low < high){
        	mid = ((high - low) >>> 1) + low;    //(low + high) / 2 (オーバーフロー対策)
        	if (arr[mid] < value) {
          	low = mid + 1;
        	} else {
            high = mid;
        	}
    	}
    	return low;
		}
  //n,mの最大公約数
  public static long gcd(long n, long m){
    if(m > n) return gcd(m,n);
    if(m == 0) return n;
    return gcd(m, n%m);
  }
	//3要素のソート
	private class Pair2 implements Comparable<Pair2> {
		String s;
		int p;
		int index;
		public Pair2(String s, int p, int index) {
				this.s = s;
				this.p = p;
				this.index = index;
		}

		public int compareTo(Pair2 other) {
				if (s.equals(other.s)) {
						return other.p - this.p;
				}
				return this.s.compareTo(other.s);
		}
	}
	//c -> intに変換
public static int c2i(char c){
	if('A' <= c && c <= 'Z'){
		return c - 'A';
	}else{
		return c - 'a' + 26;
	}
}
// int -> charに変換
public static char i2c(int i){
	if(0 <= i && i < 26){
			return (char)(i + 'A');
	}else{
			return (char)(i + 'a' - 26);
	}
}

}
