class Kamus:
    def __init__(self):
        self.data = {}
 
    def tambah(self, kata, sinonim):
        if kata not in self.data:
            self.data[kata] = []
 
        for s in sinonim:
            if s == kata:
                continue
 
            if s not in self.data[kata]:
                self.data[kata].append(s)
 
            if s not in self.data:
                self.data[s] = []
 
            if kata not in self.data[s]:
                self.data[s].append(kata)
 
    def ambilSinonim(self, kata):
        if kata not in self.data:
            return None
 
        return self.data[kata]
 
kamus = Kamus()
 
kamus.tambah("big", ["large", "great"])
kamus.tambah("big", ["huge", "fat"])
kamus.tambah("huge", ["enormous", "gigantic"])
 
# Input kata
kata = input()
 
print(kamus.ambilSinonim(kata))