#include <iostream>
#include <vector>
#include <cstdio>
#include <queue>

using namespace std;

const int NodMax = 50005;
const int MuchMax = 100005;

queue < int > Q;
vector < int > G[MuchMax];

int N, M;
int dg[NodMax], rez[NodMax];

void Read()
{
    scanf("%d %d", &N, &M);

    for(int i=1; i<=N; ++i)
    {
        int x, y;
        scanf("%d %d", &x, &y);
        G[x].push_back(y);
        ++dg[y];
    }
}

void TopSort()
{
    for(int i=1; i<=N; ++i)
        if(!dg[i])
            Q.push(i);

    while(!Q.empty())
    {
        int nodc=Q.front();
        Q.pop();
        rez[++rez[0]]=nodc;

        vector < int > ::iterator it;
        for(it=G[nodc].begin(); it!=G[nodc].end(); ++it)
        {
            --dg[*it];
            if(!dg[*it])
                Q.push(*it);
        }

    }
}

int main()
{
    freopen("sortaret.in", "r", stdin);
    freopen("sortaret.out", "w", stdout);

    Read();
    TopSort();

    for(int i=1; i<=rez[0]; ++i)
    printf("%d ", rez[i]);

    return 0;
}