def popcount(x):
    x = x - ((x >> 1) & 0x55555555)
    x = (x & 0x33333333) + ((x >> 2) & 0x33333333)
    x = (x + (x >> 4)) & 0x0f0f0f0f
    x = x + (x >> 8)
    x = x + (x >> 16)
    return x & 0x0000007f

N = int(input())
K = input()
mod = 10**9+7

def solve(S,N):
    if N==0:
        s_l = S & 1
        s15_l = (15-S) & 1
        return abs(s15_l-s_l) + 1
    res = 0
    for l in range(4):
        s_l = S>>l & 1
        s15_l = (15-S)>>l & 1

        if N==1:
            res += abs(s15_l-s_l)+1
            continue

        p = popcount(S)
        A = s_l * pow(2,3*N-3,mod) + p * pow(2,2*N-4,mod) * (pow(2,N-1,mod)-1)
        A %= mod

        q = popcount(15-S)
        B = s15_l * pow(2,3*N-3,mod) + q * pow(2,2*N-4,mod) * (pow(2,N-1,mod)-1)

        if s_l > s15_l:
            res += A-B+pow(2,2*N-2,mod)
            res %= mod
        else:
            res += B-A+pow(2,2*N-2,mod)
            res %= mod

    return res

res = 0
for i in range(8):
    if K[i]=="o":
        res += solve(i,N)
        res %= mod

print(res)