import std.conv, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.container, std.math, std.range, std.regex, std.typecons;
import core.bitop, core.thread;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) throw new EOFException; tokens = readln.split; } auto token = tokens[0]; tokens.popFront; return token; }
int readInt() { return readToken().to!int; }
long readLong() { return readToken().to!long; }
real readReal() { return readToken().to!real; }

void chmin(T)(ref T t, in T f) { if (t > f) t = f; }
void chmax(T)(ref T t, in T f) { if (t < f) t = f; }

int binarySearch(T)(in T[] as, in bool delegate(T) test) { int low = -1, upp = cast(int)(as.length); for (; low + 1 < upp; ) { int mid = (low + upp) >> 1; (test(as[mid]) ? low : upp) = mid; } return upp; }
int lowerBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a < val)); }
int upperBound(T)(in T[] as, in T val) { return as.binarySearch((T a) => (a <= val)); }


void update(long[] bit, int pos, long val) {
  for (int x = pos; x < cast(int)(bit.length); x |= x + 1) {
    chmax(bit[x], val);
  }
}
long getMax(long[] bit, int pos) {
  long ret = 0;
  for (int x = pos - 1; x >= 0; x = (x & (x + 1)) - 1) {
    chmax(ret, bit[x]);
  }
  return ret;
}

int N;
int[] H;
long[] A;

void main() {
  try {
    for (; ; ) {
      N = readInt();
      H = new int[N];
      A = new long[N];
      foreach (i; 0 .. N) {
        H[i] = readInt() - 1;
      }
      foreach (i; 0 .. N) {
        A[i] = readLong();
      }
      long ans = -1;
      auto bit = new long[N];
      bit[] = 0;
      foreach (i; 0 .. N) {
        const res = bit.getMax(H[i]);
        chmax(ans, res + A[i]);
        bit.update(H[i], res + A[i]);
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}
