from typing import List
from collections import deque
from collections import Counter

class TopoSort:
    # edges是边列表, (a, b)代表一条边，表示a依赖于b, 返回拓扑排序之后的节点列表, 无法完成拓扑排序返回None
    @staticmethod
    def sort(edges: List):
        dep_cnt = Counter()    # 每一个节点的依赖计数
        link = {}

        for a, b in edges:
            if a not in link:
                link[a] = []
            if b not in link:
                link[b] = []

            link[b].append(a)       # link[b]记录哪些点依赖b
            if a not in dep_cnt:
                dep_cnt[a] = 0
            if b not in dep_cnt:
                dep_cnt[b] = 0

            dep_cnt[a] += 1

        ans = []
        valid_node = deque()        # 当前入度为0的所有节点
        for node, degree in dep_cnt.items():
            if degree == 0:
                valid_node.append(node)

        while len(ans) < len(link):
            if len(valid_node) == 0:
                return None

            cur_node = valid_node.popleft()
            for next in link[cur_node]:
                dep_cnt[next] -= 1
                if dep_cnt[next] == 0:
                    valid_node.append(next)

            ans.append(cur_node)

        return ans

n, m = map(int, input().split())
edges = []
for i in range(m):
    a, b = map(int, input().split())
    edges.append((b, a))
topo = TopoSort()
ans = topo.sort(edges)
if ans is None:
    print(-1)
else:
    print( ' '.join(map(str, ans)) )