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class Solution:
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    def validateStackSequences(self, pushed: List[int], popped: List[int]) -> bool:
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        stack = []
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        i = 0
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        for num in pushed:
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            stack.append(num)  # we are pushing the number to the stack
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            while len(stack) > 0 and stack[len(stack) - 1] == popped[i]:
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                # if the last element of the stack is equal to the popped element
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                stack.pop()
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                i += 1  # we are incrementing i
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        return True if len(stack) == 0 else False