n=int(input()) s=list(input()) a=list(map(int,input().split())) L1=[] L2=[] for i in range(n): if s[i]=='R': L1.append(a[i]) L2.append(-a[i]) else: L1.append(-a[i]) L2.append(a[i]) ans1=[] ans2=[] ct1=0 ct2=0 for i in range(n): ct1+=L1[i] if ct1<0: ct1=0 ans1.append(ct1) ct2+=L2[i] if ct2<0: ct2=0 ans2.append(ct2) print(max(ans1+ans2))