#include <stdio.h>
int main ()
{
int n = 0;
int m = 0;
int d = 0;
scanf("%d", &n);
scanf("%d", &m);
scanf("%d", &d);
int tab[200002];
for (int i = 0; i < 200002; i++)
{
tab[i] = 0;
}
int tmp = 0;
int tmp1 = 0;
int tmp2 = 0;
for (int i = 0; i < m; i++)
{
scanf("%d", &tmp);
scanf("%d", &tmp1);
tab[tmp] = tab[tmp] + 1;
tab[tmp1] = tab[tmp1] + 1;
}
for (int i = 1; i <= n; i++)
{
if (tab[i] >= d)
{
tmp2 = tmp2 + 1;
}
}
if (tmp2 >= 3)
{
printf("%d\n",tmp2);
for (int i = 1; i <= n; i++)
{
if (tab[i] >= d)
{
printf("%d ",i);
}
}
}
else
printf("NIE");
printf("\n");
}