good set trie

class Trie:
    def __init__(self):
        self.nodes = dict()
        self.end = False

    def insert(self, s, i):
        if i == len(s) - 1:
            self.end = True
            if len(self.nodes):
                return False
            return True
        if self.end:
            return False
        if s[i] not in self.nodes:
            self.nodes[s[i]] = Trie()
        return self.nodes[s[i]].insert(s, i+1)

w = input().split()
flg = True
t = Trie()
for x in w:
    v = t.insert(x, 0)
    if not v:
        flg = False
        break

print("Good" if flg else "not good")