Condensation

from collections import defaultdict

n, m = map(int, input().split())
g = defaultdict(list)
for i in range(m):
    a, b = map(int, input().split())
    g[a].append(b)


topsort = []

visited_ts = set()

def dfs_ts(node):
    if not node in visited_ts:
        visited_ts.add(node)
        for neigh in g[node]:
            dfs_ts(neigh)
        topsort.append(node)


for v in range(1, n+1):
    if v not in visited_ts:
        dfs_ts(v)

g_rev = defaultdict(list)

for v, neighbors in g.items():
    for neigh in neighbors:
        g_rev[neigh].append(v)

count = 0
res = []

visited = [0] * (n + 1)

def dfs(node, comp):
    if not visited[node]:
        visited[node] = comp
        for neigh in g_rev[node]:
            dfs(neigh, comp)

for v in reversed(topsort):
    if not visited[v]:
        count += 1
        dfs(v, count)

print(count)
print(' '.join([str(comp) for comp in visited[1:]]))