s = list(input())
kai = 'kyoprotenkei90'
kai_dic = {}
for i in list(kai):
    if i in kai_dic:
        kai_dic[i] += 1
    else:
        kai_dic[i] = 1
for i in s:
    if i in kai_dic:
        if kai_dic[i]:
            kai_dic[i] -= 1
        else:
            print('No')
            exit()
    else:
        print('No')
        exit()
if not sum(kai_dic.values()):
    print('Yes')
else:
    print('No')