uva - 10305

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

struct result
{
    int time;
    int node;
};

bool compare(result a, result b)
{
    return a.time > b.time;
}

int start[1000];
int finish[1000];
int time;
int visited[1000];
vector<int> v[100000];
vector<result> r;
int n, m;

void DFS_visit(int source)
{
    start[source] = time++;
    visited[source] = 1;
    for (int i = 0; i < v[source].size(); i++)
    {
        int a = v[source][i];
        if (visited[a] != 1)
        {
            DFS_visit(a);
        }
    }
    finish[source] = time++;
}

void DFS()
{
    for (int i = 1; i <= n; i++)
    {
        if (visited[i] != 1)
        {
            DFS_visit(i);
        }
    }
}


int main()
{
    while (cin >> n >> m)
    {

        if (n == 0 && m == 0)break;
        time = 0;

        for (int i = 0; i < 1000; i++)
        {
            visited[i] = start[i] = finish[i] = 0;
        }

        int a, b;
        for (int i = 0; i < m; i++)
        {
            cin >> a >> b;
            v[a].push_back(b);
        }

        DFS();

        result k;

        for (int i = 1; i <= n; i++)
        {
            k.time = finish[i];
            k.node = i;
            r.push_back(k);
        }
        sort(r.begin(), r.end(), compare);

        for (int i = 0; i < r.size() - 1; i++)
        {
            cout << r[i].node << " ";
        }
        cout << r[n - 1].node << endl;
        r.clear();
        for (int i = 0; i < 100000; i++)
        {
            v[i].clear();
        }
    }
    return 0;
}


/*

5 4
1 2
2 3
1 3
1 5
0 0

*/