import string



# print(type(string.ascii_lowercase))

input = eval(input())

alphabets = string.ascii_lowercase



# print(alphabets.index(input))

i = alphabets.index(input)

ans = alphabets[i + 1]

  

print(ans)
from string import ascii_lowercase as alphabets



input = eval(input())

print((alphabets[alphabets.index(input) + 1]))
import string

# print(type(string.ascii_lowercase))
input = eval(input())
alphabets = string.ascii_lowercase
# print(alphabets.index(input))
i = alphabets.index(input)
ans = alphabets[i + 1]
print(ans)

from string import ascii_lowercase as alphabets

input = eval(input())
print((alphabets[alphabets.index(input) + 1]))

-import string +from string import ascii_lowercase as alphabets -# print(type(string.ascii_lowercase)) -alphabets = string.ascii_lowercase -# print(alphabets.index(input)) -i = alphabets.index(input) -ans = alphabets[i + 1] -print(ans) +print((alphabets[alphabets.index(input) + 1]))