how to write code for this in Python.. please help me

Question

faded palindrome or smallest palindrome

Given a string S having characters from English alphabets ['a' - 'z'] and '.' as the special character (without quotes). 
Write a program to construct the lexicographically smallest palindrome by filling each of the faded character ('.') with a lower case alphabet.

Definition:

The smallest lexicographical order is an order relation where string s is smaller than t, given the first character of s (s1 ) is smaller than the first character of t (t1), or in case they

are equivalent, the second character, etc.

For example "aaabbb" is smaller than "aaac" because although the first three characters

are equal, the fourth character b is smaller than the fourth character c. 

Input Format: 
String S

Output Format: 
Print lexicographically smallest palindrome after filling each '.' character, if it

possible to construct one. Print -1 otherwise.

Answer 1

Hey, please check this possible solution:

https://code.sololearn.com/czN2vHPU6myq/#py

Answer 2

that is right i am also thinking how can i do this but now it is easy for me

Answer 3

a=input()
l=len(a)
if a[0]!=a[l-1]:
print("-1",end="")
else:
for i in range(l):
if a[i]==".":
if a[(l-1)-i]!=".":
print(a.replace(".",a[(l-1)-i]),end="")
break
else:
print(a.replace(".","a"),end="")
break