#include<fstream.h>
#include<stdlib.h>
#define nx 50005
int *a[nx],g[nx],Q[nx];
int n,m;

int main()
 {
  ifstream be ("sortaret.in");
  ofstream ki ("sortaret.out");
  int i,j,x,y;
  be>>n>>m;
  for (i=1;i<=n;++i)
   {
    a[i]=(int*)realloc(a[i],sizeof(int));
    a[i][0]=0;
   }
  for (i=1;i<=n;++i)
   {
    be>>x>>y;
    a[x][0]++;
    a[x]=(int*)realloc(a[x],(a[x][0]+1)*sizeof(int));
    a[x][a[x][0]]=y;
    g[y]++;
   }
  be.close();
  for (i=1;i<=n;++i)
   if (!g[i])
    Q[++Q[0]]=i;
  int r,p;
  for (j=1;j<=n;++j)
   {
    r=Q[j];
    for (i=1;i<=a[r][0];++i)
     {
      p=a[r][i];
      g[p]--;
      if (!g[p])
	Q[++Q[0]]=p;
     }
   }
  for (i=1;i<=Q[0];++i)
    ki<<Q[i]<<" ";
  ki<<'\n';
  ki.close();
  return 0;
 }