#include <fstream>
#include <queue>
#include <vector>

#define NMAX 50007

using namespace std;

ifstream cin("sortaret.in");
ofstream cout("sortaret.out");

queue < int > q;
vector < int > v[NMAX], Ans;
int Ap[NMAX];
int n, m;

void bfs(){
    while(! q.empty()){
        int Node = q.front();
        Ans.push_back(Node);
        q.pop();
        for(vector < int > :: iterator it = v[Node].begin(); it != v[Node].end(); ++it){
            --Ap[*it];
            if(Ap[*it] == 0)
                q.push(*it);
        }
    }
}

int main(){
    cin >> n >> m;
    for(int i = 1; i <= n; ++i){
        int A, B;
        cin >> A >> B;
        v[A].push_back(B);
        ++Ap[B];
    }
    for(int i = 1; i <= n; ++i)
        if(Ap[i] == 0)
            q.push(i);
    bfs();
    for(vector < int > :: iterator it = Ans.begin(); it != Ans.end(); ++it)
        cout << *it << " ";
    return 0;
}