Built-in Function Solutions:

Time Complexity : O(n) - s.swapcase() iterates through each character in the string s

Space Complexity: O(n) s.swapcase() returns a new string with the case of each letter swapped.

Strings in Python are immutable, so a new string of the same length is created in memory.

📌 Why? A new string of size n is returned → linear space → O(n)

def swap_case(s):

    
    return s.swapcase()
 

if __name__ == '__main__':
    s = input()
    result = swap_case(s)
    print(result)