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

#define NMAX 50005

int n,m,inc[NMAX];
vector<int>g[NMAX];
queue<int>q;
signed main(){
#ifndef LOCAL
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
#endif // LOCAL
    freopen("sortaret.in","r",stdin);
    freopen("sortaret.out","w",stdout);
    cin>>n>>m;
    for(int i=1;i<=n;++i){
        int x,y;
        cin>>x>>y;
        g[x].push_back(y);
        ++inc[y];
    }
    for(int i=1;i<=n;++i){
        if(inc[i])continue;
        q.push(i);
    }
    while(!q.empty()){
        int i=q.front();
        q.pop();
        cout<<i<<" ";
        for(const auto&it:g[i]){
            --inc[it];
            if(!inc[it]){
                q.push(it);
            }
        }
    }
    return 0;
}