yukicoder = "yukicoder"
P = 10 ** 9 + 7
N = int(input())
S = input()
X = [0] * 10 # without ?
Y = [0] * 10 # with ?
X[0] = 1
for s in S:
    for i in range(9):
        if s == yukicoder[i]:
            X[i+1] = (X[i+1] + X[i]) % P
            Y[i+1] = (Y[i+1] + Y[i]) % P
            break
    else:
        for i in range(9):
            Y[i+1] = (Y[i+1] + X[i]) % P

print((X[9] + Y[9]) % P)