class Vertex:

    def __init__(self, n):
        self.name = n
        self.neighbors = set()

    def add_neighbor(self, v):
        self.neighbors.add(v)


class Graph:
    vertices = {}

    def add_vertex(self, vertex):

        if isinstance(vertex, Vertex) and vertex.name not in self.vertices:
            self.vertices[vertex.name] = vertex
            return True
        else:
            return False

    def add_edge(self, u, v):
        if u in self.vertices and v in self.vertices:
            self.vertices[u].add_neighbor(v)
            self.vertices[v].add_neighbor(u)
            return True

        else:
            return False

    def print_graph(self):

        for key in sorted(self.vertices.keys()):
            print(key, sorted(list(self.vertices[key].neighbors)))


if __name__ == '__main__':
    g = Graph()
    a = Vertex('A')
    g.add_vertex(Vertex('B'))

    for i in range(ord('A'), ord('K')):
        g.add_vertex(Vertex(chr(i)))

    edges = ['AB', 'AE', 'BF', 'CG', 'DE', 'DH', 'EH', 'FG', 'FJ', 'GJ', 'FH']

    for edge in edges:
        g.add_edge(edge[0], edge[1])

    g.print_graph()

class Vertex:

    def __init__(self, n):
        self.name = n
        self.neighbors = set()

    def add_neighbor(self, v):
        self.neighbors.add(v)


class Graph:
    vertices = {}

    def add_vertex(self, vertex):

        if isinstance(vertex, Vertex) and vertex.name not in self.vertices:
            self.vertices[vertex.name] = vertex
            return True
        else:
            return False

    def add_edge(self, u, v):
        if u in self.vertices and v in self.vertices:
            self.vertices[u].add_neighbor(v)
            self.vertices[v].add_neighbor(u)
            return True

        else:
            return False

    def print_graph(self):

        for key in sorted(self.vertices.keys()):
            print(key, sorted(list(self.vertices[key].neighbors)))


if __name__ == '__main__':
    g = Graph()
    a = Vertex('A')
    g.add_vertex(Vertex('B'))

    for i in range(ord('A'), ord('K')):
        g.add_vertex(Vertex(chr(i)))

    edges = ['AB', 'AE', 'BF', 'CG', 'DE', 'DH', 'EH', 'FG', 'FJ', 'GJ', 'FH']

    for edge in edges:
        g.add_edge(edge[0], edge[1])

    g.print_graph()
