'''
Imagine a (literal) stack of plates. If the stack gets too high, it might topple. Therefore, in real life, we would likely start a new stack whe nthe previous stack exceeds some threshold. Implment a data structure SetOfStacks that mimics this. SetOfStacks should be composed of several stacks and should create a new stack once the previouse one exceeds capacity. SetOfStacks.push() and SetOfStacks.pop() should behave identically to a single stack (that is, pop() should return the same values as it would if there were just a single stack).

Follow up: Implement a function popAt(int index) which performs a pop operation on a specific sub-stack.

Hints: 64, 81
'''


def stack_of_plates(s):
    pass

if __name__ == '__main__':
    assert stack_of_plates('') ==
    assert stack_of_plates('') ==
    assert stack_of_plates('') ==
    assert stack_of_plates('') ==
    assert stack_of_plates('') ==
