N = int(input())
S = list(input())
mod = 10 ** 9 + 7
y = "yukicoder"
M = len(y)
pre0 = [0] * (M + 2)
pre1 = [0] * (M + 2)
pre0[0] = 1
for i in range(N):
    dp0 = [0] * (M + 1)
    dp1 = [0] * (M + 1)
    for j in range(M):
        dp0[j] += pre0[j]
        dp1[j] += pre1[j]
        if S[i] == "?":
            dp1[j + 1] += pre0[j]
        elif S[i] == y[j]:
            dp0[j + 1] += pre0[j]
            dp1[j + 1] += pre1[j]
        dp0[j] %= mod
        dp1[j] %= mod
        dp0[j + 1] %= mod
        dp1[j + 1] %= mod
    dp0, pre0 = pre0, dp0
    dp1, pre1 = pre1, dp1
print( (pre0[M] + pre1[M]) % mod )