def solv():
    N, K = map(int, input().split())
    graph = [[] for i in range(N + 1)]
    indeg = [0] * (N + 1)

    for i in range(K):
        a, b = map(int, input().split())
        graph[a].append(b)
        indeg[b] += 1

    zero = []
    #   a --> b --> 2 <-- c
    #     \-> d
    for i in range(1, N + 1):
        if indeg[i] == 0:
            zero.append(i)
    # print(parents)
    result = [zero[:]]
    seen = len(zero)
    while zero:
        tmp = []
        for i in zero:
            for j in graph[i]:
                indeg[j] -= 1
                if indeg[j] == 0:
                    tmp.append(j)
                    seen += 1
        if tmp:
            result.append(tmp[:])
        zero = tmp

    # print(result,graph)
    if seen != N:
        print("0")
        return
    if len(result) == N:
        print("1")
        for i in result:
            print(*i, end=" ")
    else:
        # result=[ [1,2,3], [4,5]]
        print("2")
        for i in result:
            print(*i, end=" ")
        print()
        for i in result:
            print(*i[::-1], end=" ")


solv()