N = int(input())
A = list(map(int,input().split()))
S = input()
s = []
B = []
i = 0
s.append(S[0])
B.append(A[0])
for i in range(1,N):
    if S[i] == S[i-1]:
        B[-1] += A[i]
    else:
        s.append(S[i])
        B.append(A[i])
S = "".join(s)
A = B
N = len(S)
ans = 0
P = 10 ** 9 + 7
for i in range(N):
    if S[i] != S[0]:continue
    if A[i] < A[0]:
        ans += A[i] * (A[i]+1) // 2
        ans %= P
    else:
        d = A[i] - A[0]
        ans += A[0] * d
        ans %= P
        ans += A[0] * (A[0] + 1) // 2
        ans %= P
        j = 1
        while i + j < N and S[j] == S[i+j]:
            ans += min(A[j],A[i+j])
            ans %= P
            if A[j] != A[i+j]:
                break
            else:
                j += 1
print(ans)