def check_edge(a, b, components):

    for component in components:
        if a in component or b in component:
            component.add(a)
            component.add(b)
            return

    components.append({a, b})

n, m = list(map(int, input().split()))

components = []

vertices_to_be_processed = {i for i in range(1, n + 1)}

for i in range(0, m):
    a, b = list(map(int, input().split()))

    check_edge(a, b, components)

    vertices_to_be_processed.discard(a)
    vertices_to_be_processed.discard(b)

for vertex in vertices_to_be_processed:
    components.append({vertex})

flag = True
while flag:
    flag = False
    l = len(components)
    i = 0
    while i < l - 1:
        if set.intersection(components[i], components[i+1]):
            l -= 1
            components[i] = set.union(components[i], components[i+1])
            del components[i+1]
            flag = True
        else:
            i += 1

print(len(components))

for component in components:
    print(len(component))
    print(*component)