#include<fstream.h>
 fstream f("date.in",ios::in);
 fstream g("date.out",ios::out);
 int n,m,a[100],b[100];
 void citire()
    { int x,y,i;
      f>>n>>m;
      for(i=1;i<=m;i++)
	{ f>>x>>y;
	  a[x]++;
	  b[y]++;
	}
    }
 void main()
    { citire();
      int i;
      for(i=1;i<=n;i++)
      if(a[i]==b[i]) g<<i<<" ";
    }