class Solution(object):
    def simplifyPath(self, path):
        """
        :type path: str
        :rtype: str
        """
        stack, tokens=[], path.split("/")
        for token in tokens:
            if token=='..' and stack:
                stack.pop()
            elif token!='.' and token!='..' and token:
                stack.append(token)
        return '/'+'/'.join(stack)