#include <bits/stdc++.h>

using namespace std;
vector<int>vecini[100001];
vector<bool>viz;
queue <int>q;
vector<int>ans;
vector<int>gradint;
void bfs()
{

    while(!q.empty())
    {
        int x=q.front();
        ans.push_back(x);
        for(auto z:vecini[x])
        {
            if(!viz[z])
            {
                gradint[z]--;
                if(gradint[z]==0)
                {
                    viz[z]=true;
                    q.push(z);
                }
            }
        }
        q.pop();
    }
}
int main()
{
    freopen("sortaret.in","r",stdin);
    freopen("sortaret.out","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n, m;
    cin>>n>>m;
    gradint=vector<int>(n+1,0);
    viz=vector<bool>(n+1,false);
    for(int i=1; i<=n; i++)
    {
        int a, b;
        cin>>a>>b;
        gradint[b]++;
        vecini[a].push_back(b);
    }
    for(int i=1; i<=n; i++)
    {
        if(gradint[i]==0)
        {
            viz[i]=true;
            q.push(i);

        }
    }
    bfs();
    for(auto b:ans)
    {
        cout<<b<<" ";
    }
    return 0;
}