from itertools import pairwise


def accum_dp(xs: list, f, op, e, init: dict):
    dp = init.copy()
    for x in xs:
        pp = {}
        dp, pp = pp, dp
        for fm_key, fm_val in pp.items():
            for to_key, to_val in f(fm_key, fm_val, x):
                dp[to_key] = op(dp.get(to_key, e), to_val)

    return dp


def op(a, b):
    return (a + b) % MOD


def f(k, v, x):
    # k : (?の使用回数, 最後にマッチした文字)
    cnt, ch = k

    yield k, v  # 採用しない

    # 採用する
    for (a, b) in pairs:
        if (ch, x) == (a, b):
            yield (cnt, x), v

        if ch == a and x == '?' and cnt < 1:
            yield (cnt+1, b), v


MOD = 10**9 + 7
N = int(input())
S = input()

pairs = list(pairwise('^yukicoder'))
init = {(0, '^'): 1}
dp = accum_dp(S, f, op, 0, init)

ans = 0
for (_, ch), v in dp.items():
    if ch == 'r':
        ans += v
        ans %= MOD

print(ans)