x=input()
def is_isogram(word): 

    c = word.lower() 
    letter_list = [] 
    for i in c: 
  
        if i.isalpha(): 
            if i in letter_list: 
                return("No")
            letter_list.append(i) 
  
    return ("Yes")
c=is_isogram(x)
print(c)

7e6af2e3ca640303ef4ad4e40f9d838a36acf022
<mask token>

<mask token>


def is_isogram(word):
    c = word.lower()
    letter_list = []
    for i in c:
        if i.isalpha():
            if i in letter_list:
                return 'No'
            letter_list.append(i)
    return 'Yes'


<mask token>

<mask token>


def is_isogram(word):
    c = word.lower()
    letter_list = []
    for i in c:
        if i.isalpha():
            if i in letter_list:
                return 'No'
            letter_list.append(i)
    return 'Yes'


<mask token>
print(c)

x = input()


def is_isogram(word):
    c = word.lower()
    letter_list = []
    for i in c:
        if i.isalpha():
            if i in letter_list:
                return 'No'
            letter_list.append(i)
    return 'Yes'


c = is_isogram(x)
print(c)

x=input()
def is_isogram(word): 

    c = word.lower() 
    letter_list = [] 
    for i in c: 
  
        if i.isalpha(): 
            if i in letter_list: 
                return("No")
            letter_list.append(i) 
  
    return ("Yes")
c=is_isogram(x)
print(c)
