def dfs(k, edges, visited, a):
    visited[k] = 1
    for e in edges[k]:
        if visited[e] == 0:
            dfs(e, edges, visited, a)
        elif visited[e] == 1:
            raise Exception
    a.append(k + 1)
    visited[k] = 2


N, M = map(int, input().split())
edges = [list() for _ in range(N)]
visited = [0 for _ in range(N)]
for _ in range(M):
    x, y = map(int, input().split())
    edges[x - 1].append(y - 1)
a = []
loop = False
for k in range(N):
        try:
            if not visited[k]:
                dfs(k, edges, visited, a)
        except Exception:
            loop = True
            print(-1)
            break
if not loop:
    print(*a[::-1])