from string import ascii_lowercase as lower

print((lower[lower.find(eval(input()))+1]))
print((chr(ord(eval(input()))+1)))
from string import ascii_lowercase as lower

print((lower[lower.find(eval(input())) + 1]))

print((chr(ord(eval(input())) + 1)))

-from string import ascii_lowercase as lower - -print((lower[lower.find(eval(input())) + 1])) +print((chr(ord(eval(input())) + 1)))