import java.io.*;
import java.util.*;
import java.math.*;

class Main {
	
	public static void out (Object o) {
		System.out.println(o);
	}
	
	public static int solve (int[] levelM , int[] levelE) {
		int len = levelM.length;
		Arrays.sort(levelM);
		for (int i = 0; i < len; i++) {
			int upIndex = 0;
			int min = levelM[0] & 0xfff;
			for (int j = 1; j < len && levelM[0] >> 12 == levelM[j] >> 12; j++) {
				int f = levelM[j] & 0xfff;
				if (f < min) {
					min = f;
					upIndex = j;
				}
			}
			levelM[upIndex]++;
			levelM[upIndex] += (levelE[i] >> 1) << 12;
			Arrays.sort(levelM);
		}
		int ret = 0;
		for (int i = 0; i < len; i++)
			ret = Math.max(ret , levelM[i] & 0xfff);
		return ret;
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		int len = Integer.parseInt(br.readLine());
		String[] line1 = br.readLine().split(" ");
		int[] levelM = new int[len];
		String[] line2 = br.readLine().split(" ");
		int[] levelE = new int[len];
		
		for (int i = 0; i < len; i++) {
			levelM[i] = Integer.parseInt(line1[i]) << 12;
			levelE[i] = Integer.parseInt(line2[i]);
		}
		
		out(solve(levelM , levelE));
	}
}