백준 11655 python

def ROT13(S):
    #print("ROT13 시작")
    result = ''

    for char in S:
        #print("암호화 전 char : ", char)
        if 'A' <= char <= 'Z':
            char = ord(char) + 13
            if char > 90:
                char -= 26
            result += chr(char)
        elif 'a' <= char <= 'z':
            char = ord(char) + 13
            if char > 122:
                char -= 26
            result += chr(char)
        else :
            result += char
        #print("암호화 후 char : ", char)
        #print("result : ", result)

    return result

S = input()
print(ROT13(S))