Ordering tasks

Input

Consists of several instances of the problem. Each instance begins with a line containing two integers: number of tasks $n$ (1 \le n \le 100), numbered from $1$ to $n$ and number $m$ 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 is not processed and terminates the input data.

Output

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

Examples