Why does it output that i dumbed the program

Question

The Spy Life

You are a secret agent, and you receive an encrypted message that needs to be decoded. The code that is being used flips the message backwards and inserts non-alphabetic characters in the message to make it hard to decipher.

Task:
Create a program that will take the encoded message, flip it around, remove any characters that are not a letter or a space, and output the hidden message.

Input Format:
A string of characters that represent the encoded message.

Output Format:
A string of character that represent the intended secret message.

Sample Input:
d89%l++5r19o7W *o=l645le9H

Sample Output:
Hello World
https://code.sololearn.com/c01ggA3z1SzB/?ref=app

Answer 1

Why you long unsigned int for i?
After i = 0 then i-- causes long int max value...
Use just
int i;