## 22 Nov Aurora Wednesday 18:30 Python Practice 22.11.16.

**Question:**

John has n tasks to do. Unfortunately, the tasks are not independent and the execution of one task is only possible if other tasks have already been executed.

**Input**

The input will consist of several instances of the problem. Each instance begins with a line containing two integers, 1 ≤ n ≤ 100 and m. n is the number of tasks (numbered from 1 to n) and m is the number of direct precedence relations between tasks. After this, there will be m lines with two integers i and j, representing the fact that task i must be executed before task j.

An instance with n = m = 0 will finish the input.

**Output**

For each instance, print a line with n integers representing the tasks in a possible order of execution.

Sample Input 5 4 1 2 2 3 1 3 1 5 0 0 Sample Output 1 4 2 5 3

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