# question 1
def rotateR(val):
    return val[-1] + val[:-1] if len(val) > 0 else None









# question 4
def rotateRx(val):
    pass



# question 5
def rotateRx_modified(val):
    # cannot be modified to work for strings, without returning a value. Python strings are immutable. They cannot be
    # modified once they are created:
    # ```TypeError: 'str' object does not support item assignment```
    # So the only way to achieve this would be to return a value and assign it back.
    pass

# question 6
def rotateR2(val):
    return rotateR(rotateR(val))