Vasya has a string s of length n consisting only of digits 0 and 1. Also he has an array a of length n. 

Vasya performs the following operation until the string becomes empty: choose some consecutive substring of equal characters, erase it from the string and glue together the remaining parts (any of them can be empty). For example, if he erases substring 111 from string 111110 he will get the string 110. Vasya gets a_x points for erasing substring of length x.

Vasya wants to maximize his total points, so help him with this! 

Input

The first line contains one integer n (1 ≤ n ≤ 100) — the length of string s.

The second line contains string s, consisting only of digits 0 and 1.

The third line contains n integers a_1, a_2, ... a_n (1 ≤ a_i ≤ 10^9), where a_i is the number of points for erasing the substring of length i.

Output

Print one integer — the maximum total points Vasya can get.

Examples

Input


7
1101001
3 4 9 100 1 2 3


Output


109


Input


5
10101
3 10 15 15 15


Output


23

Note

In the first example the optimal sequence of erasings is: 1101001 → 111001 → 11101 → 1111 → ∅.

In the second example the optimal sequence of erasings is: 10101 → 1001 → 11 → ∅.
import java.io.*;
import java.util.*;

public class E implements Runnable{
	public static void main (String[] args) {new Thread(null, new E(), "_cf", 1 << 28).start();}

	int n;
	char[] str;
	int[] a;
	long[][][][] dp;
	
	public void run() {
		FastScanner fs = new FastScanner();
		PrintWriter out = new PrintWriter(System.out);
		System.err.println("Go!");

		n = fs.nextInt();
		str = fs.next().toCharArray();
		a = fs.nextIntArray(n);
		dp = new long[3][n][n+1][n+1];
		for(int i = 0; i < dp.length; i++) {
			for(int j = 0; j < dp[i].length; j++) {
				for(int k = 0; k < dp[i][j].length; k++) {
					Arrays.fill(dp[i][j][k], -1);
				}
			}
		}
		out.println(solve(2, 0, n, 0));
		
		out.close();
	}
	
	long solve(int value, int idx, int end, int len) {
		if(idx == end) {
			if(len == 0) return 0;
			return a[len-1];
		}
		long ret = dp[value][idx][end][len];
		if(ret != -1) return ret;
		
		long res = 0;
		if(len > 0) {
			//stop this chain
			res = Math.max(res, a[len-1] + solve(2, idx, end, 0));
		}
		
		for(int next = idx; next < end; next++) {
			if(value != 2 && str[next]-'0' != value) continue;
			//include as the next?
			ret = 0;
			if(next > idx) ret = solve(2, idx, next, 0);
			ret += solve(str[next]-'0', next+1, end, len+1);
			res = Math.max(res, ret);
		}
		
		return dp[value][idx][end][len] = res;
	}

	class FastScanner {
		public int BS = 1<<16;
		public char NC = (char)0;
		byte[] buf = new byte[BS];
		int bId = 0, size = 0;
		char c = NC;
		double num = 1;
		BufferedInputStream in;

		public FastScanner() {
			in = new BufferedInputStream(System.in, BS);
		}

		public FastScanner(String s) throws FileNotFoundException {
			in = new BufferedInputStream(new FileInputStream(new File(s)), BS);
		}

		public char nextChar(){
			while(bId==size) {
				try {
					size = in.read(buf);
				}catch(Exception e) {
					return NC;
				}                
				if(size==-1)return NC;
				bId=0;
			}
			return (char)buf[bId++];
		}

		public int nextInt() {
			return (int)nextLong();
		}

		public long nextLong() {
			num=1;
			boolean neg = false;
			if(c==NC)c=nextChar();
			for(;(c<'0' || c>'9'); c = nextChar()) {
				if(c=='-')neg=true;
			}
			long res = 0;
			for(; c>='0' && c <='9'; c=nextChar()) {
				res = (res<<3)+(res<<1)+c-'0';
				num*=10;
			}
			return neg?-res:res;
		}

		public double nextDouble() {
			double cur = nextLong();
			return c!='.' ? cur:cur+nextLong()/num;
		}

		public String next() {
			StringBuilder res = new StringBuilder();
			while(c<=32)c=nextChar();
			while(c>32) {
				res.append(c);
				c=nextChar();
			}
			return res.toString();
		}

		public String nextLine() {
			StringBuilder res = new StringBuilder();
			while(c<=32)c=nextChar();
			while(c!='\n') {
				res.append(c);
				c=nextChar();
			}
			return res.toString();
		}

		public boolean hasNext() {
			if(c>32)return true;
			while(true) {
				c=nextChar();
				if(c==NC)return false;
				else if(c>32)return true;
			}
		}

		public int[] nextIntArray(int n) {
			int[] res = new int[n];
			for(int i = 0; i < n; i++) res[i] = nextInt();
			return res;
		}

	}

}