# your code goes here

class Kamus:
    def __init__(self):
        self.graph = {}

    def tambah(self, kata, sinonim):
        if not kata or not isinstance(sinonim, (list, tuple, set)):
            return

        if kata not in self.graph:
            self.graph[kata] = set()

        for s in sinonim:
            if not s or s == kata:
                continue

            self.graph[kata].add(s)

            if s not in self.graph:
                self.graph[s] = set()
            self.graph[s].add(kata)

    def ambilSinonim(self, kata):
        if kata not in self.graph:
            return None

        if len(self.graph[kata]) == 0:
            return [kata]

        return list(self.graph[kata])