#yuki1433
n=int(input())
s=input()
a=list(map(int,input().split()))
res=0
MAX,MIN=0,0
for i in range(n):
 if s[i]=='R':
  x=a[i]
 else:
  x=-a[i]
 MAX=max(MAX+x,x)
 MIN=min(MIN+x,x)
 res=max(res,abs(MAX),abs(MIN))
print(res)