N=int(input())
S=input()
A=list(map(int,input().split()))

T=[0]
for s,a in zip(S,A):
    if s=="R":
        T.append(T[-1]+a)
    else:
        T.append(T[-1]-a)

U=T.copy()
V=T.copy()

for i in range(1,N+1):
    U[i]=min(U[i-1],U[i])
    V[i]=max(V[i-1],V[i])

X=0
for i in range(1,N+1):
    X=max(X,T[i]-U[i],V[i]-T[i])

print(X)