#D2945. Topological Sort
Topological Sort
Topological Sort
A directed acyclic graph (DAG) can be used to represent the ordering of tasks. Tasks are represented by vertices and constraints where one task can begin before another, are represented by edges. For example, in the above example, you can undertake task B after both task A and task B are finished. You can obtain the proper sequence of all the tasks by a topological sort.
Given a DAG , print the order of vertices after the topological sort.
Constraints
- There are no parallel edges in
- There are no self loops in
Input
A directed graph is given in the following format: :
is the number of vertices and is the number of edges in the graph. The graph vertices are named with the numbers respectively.
and represent source and target nodes of -th edge (directed).
Output
Print the vertices numbers in order. Print a number in a line.
If there are multiple possible solutions, print any one of them (the solution is judged by a special validator).
Example
Input
6 6 0 1 1 2 3 1 3 4 4 5 5 2
Output
0 3 1 4 5 2
inputFormat
Input
A directed graph is given in the following format: :
is the number of vertices and is the number of edges in the graph. The graph vertices are named with the numbers respectively.
and represent source and target nodes of -th edge (directed).
outputFormat
Output
Print the vertices numbers in order. Print a number in a line.
If there are multiple possible solutions, print any one of them (the solution is judged by a special validator).
Example
Input
6 6 0 1 1 2 3 1 3 4 4 5 5 2
Output
0 3 1 4 5 2
样例
6 6
0 1
1 2
3 1
3 4
4 5
5 2
0
3
1
4
5
2
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