#include<cstdio>
#include<vector>
using namespace std;
FILE *f=fopen("sortaret.in","r");
FILE *g=fopen("sortaret.out","w");
int n,m;
vector<int>Muchii[50001];
int Sortat[50001];
int nrSort;

bool viz[50001];
void read()
{
    fscanf(f,"%ld%ld",&n,&m);
    for(int i=1;i<=n;i++)
    {
        int x,y;
        fscanf(f,"%ld%ld",&x,&y);
        Muchii[x].push_back(y);
    }
}
void Resolve(int nodCurent)
{
    viz[nodCurent]=true;
    for(int j=0;j<Muchii[nodCurent].size();j++)
    {
        int vecin = Muchii[nodCurent][j];
        if(!viz[vecin])
            Resolve(vecin);
    }
    Sortat[++nrSort]=nodCurent;
}
int main()
{
    read();
    Resolve(1);
    for(int i=nrSort;i>=1;i--)
        fprintf(g,"%ld ",Sortat[i]);
    fclose(f);
    fclose(g);
    return 0;
}