class social_network:

	def __init__(self):
		self.adj_list = {}

	def input_friends(self, f1, f2):
		if f1 not in self.adj_list:
			self.adj_list[f1]=[]
		self.adj_list[f1].append(f2)

		if f2 not in self.adj_list:
			self.adj_list[f2]=[]
		self.adj_list[f2].append(f1)

	def get_neighbors(self, node):
		q=[node]
		set_nodes=set()
		while len(q)>0:
			node = q.pop()
			if node in set_nodes:
				continue
			set_nodes.add(node)
			for neigh in self.adj_list[node]:
				q.append(neigh)
		return set_nodes

	def find_disjoint_sets(self):
		list_disjoint_sets=[]
		for f1 in self.adj_list:
			#check if that node is already in disjoint sets
			flag_check = False
			#check  node exists in already added sets
			for s_nodes in list_disjoint_sets:
				if f1 in s_nodes:
					flag_check=True
			#if not is node in the already existing sets...then that becomes new disjoint set		
			if not flag_check: 
				set_nodes = self.get_neighbors(f1)
				list_disjoint_sets.append(set_nodes)

		return list_disjoint_sets

def main():
	s_obj = social_network()
	list_friends = [('a', 'b'), ('c', 'd'), ('a', 'e'), ('f', 'g'), ('g', 'h'), ('b', 'f'), ('d', 'i')]
	for v in list_friends:
		s_obj.input_friends(v[0], v[1])
	disjoint_sets = s_obj.find_disjoint_sets()
	print(disjoint_sets)

if __name__ == '__main__':
	main()