def z_algo(p):
	n=len(p)
	Z=[0]*n
	Z[0]=n
	i=1
	j=0
	while i<n:
		while i+j<n and p[j]==p[i+j]:
			j+=1
		Z[i]=j
		if j==0:
			i+=1
			continue
		k=1
		while k<j and k+Z[k]<j:
			Z[i+k]=Z[k]
			k+=1
		i+=k
		j-=k
	return Z

N=int(input())
A=list(map(int,input().split()))
S=input()
M=10**9+7
half=(M+1)//2
p=[('#',100)]*(N)
cum_sum=[0]*(N+1)
for i in range(N-1):
	p[i]=(S[i+1],A[i+1])
	cum_sum[i+1]=(cum_sum[i]+A[i+1])%M
cum_sum[N]=cum_sum[N-1]
Z=z_algo(p)
ans=0
for i in range(N):
	if S[i]!=S[0]:
		continue
	if A[i]<A[0]:
		ans+=((A[i]+1)*A[i])//2
		ans%=M 
	else:
		ans+=(A[0]*(A[i]-A[0]))
		ans%=M
		ans+=(A[0]*(A[0]+1))//2
		ans%=M
		ans+=cum_sum[Z[i]]
		if i+Z[i]+1<N and S[i+1+Z[i]]==S[1+Z[i]]:
			ans+=min(A[i+1+Z[i]],A[1+Z[i]])
		ans%=M
print(ans)