import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		char[] s = br.readLine().toCharArray();
		String[] sa = br.readLine().split(" ");
		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = Integer.parseInt(sa[i]);
		}
		br.close();

		long max = 0;
		long min = 0;
		long[] b = new long[n + 1];
		for (int i = 0; i < n; i++) {
			if (s[i] == 'R') {
				b[i + 1] = b[i] + a[i];
			} else {
				b[i + 1] = b[i] - a[i];
			}
			max = Math.max(max, b[i + 1]);
			min = Math.min(min, b[i + 1]);
		}
		System.out.println(max - min);
	}
}