Editorial

Let $c$ be the input character. Print the characters $c-1$ and $c+1$.

Algorithm realization

Read the input symbol $c$.

scanf("%c", &c);

Print the symbols $c-1$ and $c+1$.

printf("%c %c\n", c - 1, c + 1);

Python realization

Read the input symbol $c$.

c = input()

Compute and print the symbols $prev=c-1$ and $next=c+1$.

prev = chr(ord(c) - 1)
next = chr(ord(c) + 1)
print(prev, next)