from heapq import heappop, heappush import sys input = sys.stdin.readline n, m = map(int, input().split()) indegree = [0] * (n + 1) graph = [[] for _ in range(n + 1)] for _ in range(m): a, b = map(int, input().split()) graph[a].append(b) indegree[b] += 1 def topological_sort(): ans = [] h = [] for i in range(1, n + 1): if indegree[i] == 0: heappush(h, i) while h: cur = heappop(h) ans.append(cur)..