N = int(input())
cnt = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
eto = ["ne", "ushi", "tora", "u", "tatsu", "mi", "uma", "hitsuji", "saru", "tori", "inu", "i"]
for i in range(N):
    cnt[eto.index(input())] += 1

before = -1
for i in range(N):
    maxcnt = 0
    oku = -1
    for j in range(12):
        if cnt[j] > maxcnt and before != j:
            maxcnt = cnt[j]
            oku = j
    if oku == -1 and max(cnt) != 0:
        print("NO")
        exit()
    before = oku
    cnt[oku] -= 1
print("YES")