#!/usr/bin/env python3
import sys

def main():
    import itertools 
    N = int(input())
    S = input()
    A = list(map(int, input().split()))
    RmB = []
    mRB = []
    for i in range(N):
        if S[i] == "B":
            RmB.append(-A[i])
            mRB.append(A[i])
        else:
            RmB.append(A[i])
            mRB.append(-A[i])
    sRmB = [0] + list(itertools.accumulate(RmB))
    smRB = [0] + list(itertools.accumulate(mRB))
    print(max(abs(max(sRmB) - min(sRmB)), abs(max(smRB) - min(smRB))))
    return

if __name__ == '__main__':
    main()