def add(g, start, end):
	"""
	Add edge information into g

	@type: g, graph (2D array)
	@param: g, adjacency list
	@type: start, integer
	@param: start, start vertex point for edge 
	@type: end, integer
	@param: end, end vertex point for edge
	"""
	g[start].append(end)
	g[end].append(start)
	return g