Final Exam Fundamentals Decrypting Commands

text = input()

while True:
    line = input()
    if line == "Finish":
        break
    line_split = line.split()
    command = line_split[0]

    if command == "Replace":
        old_char = line_split[1]
        new_char = line_split[2]
        text = text.replace(old_char, new_char)
        print(text)

    elif command == "Cut":
        start_idx = int(line_split[1])
        end_idx = int(line_split[2])
        if 0 <= start_idx <= len(text) and 0 <= end_idx <= len(text):
            text = text[:start_idx] + text[end_idx + 1:]
            print(text)
        else:
            print("Invalid indices!")
    elif command == "Make":
        upper_lower = line_split[1]
        if upper_lower == "Upper":
            text = text.upper()
            print(text)
        else:
            text = text.lower()
            print(text)
    elif command == "Check":
        substring = line_split[1]
        if substring in text:
            print(f"Message contains {substring}")
        else:
            print(f"Message doesn't contain {substring}")
    elif command == "Sum":
        start_idx = int(line_split[1])
        end_idx = int(line_split[2])
        if 0 <= start_idx < len(text) and 0 <= end_idx < len(text):
            substring = text[start_idx: end_idx + 1]
            sum_char = 0
            for ch in substring:
                sum_char += ord(ch)
            print(sum_char)
        else:
            print("Invalid indices!")