#include <stdio.h>
#include <stdlib.h>

#define MAXV 10240

struct vert
{
  size_t deg, alloc_deg;
  struct vert **arcs;
  unsigned gen;
  unsigned dfs;
};

static struct vert verts[MAXV];
static unsigned gen; /* = 0; */

static void
add_edge (struct vert *v, struct vert *dest)
{
  if (v->deg == v->alloc_deg)
    {
      if (v->alloc_deg == 0)
	v->alloc_deg = 2;
      else
	v->alloc_deg *= 2;
      v->arcs = realloc (v->arcs, v->alloc_deg * sizeof (*v->arcs));
    }
  v->arcs[v->deg] = dest;
  v->deg++;
}

static size_t max_deg;
static unsigned dfs_index;

static unsigned
visit (struct vert *v, struct vert *parent)
{
  size_t i, min;

  if (v->gen == gen)
    return v->dfs;
  /* printf ("Enter %d: DFS %u\n", v - verts, dfs_index); */
  v->gen = gen;
  v->dfs = dfs_index;
  dfs_index++;
  min = v->dfs;
  for (i = 0; i < v->deg; i++)
    {
      if (v->arcs[i] != parent)
	{
	  unsigned d;
	  
	  d = visit (v->arcs[i], v);
	  if (min > d)
	    min = d;
	}
    }
  if (min >= v->dfs)
    {
      /* printf ("ART %d\n", v - verts); */
      if (max_deg < v->deg)
	max_deg = v->deg;
    }
  /* printf ("Leave %d: min %u\n", v - verts, min); */
  return min;
}

static void
walk (struct vert *v)
{
  size_t i, c;

  /* printf ("TL %d: DFS %u\n", v - verts, dfs_index); */
  v->gen = gen;
  v->dfs = dfs_index;
  dfs_index++;
  c = 0;
  for (i = 0; i < v->deg; i++)
    {
      if (v->arcs[i]->gen != gen)
	{
	  c++;
	  visit (v->arcs[i], v);
	}
    }
  if (max_deg < c)
    {
      /* printf ("TLART %d: %u\n", v - verts, c); */
      max_deg = c;
    }
}

int
main  (void)
{
  for (;;)
    {
      unsigned n, m, comps;
      struct vert *v;

      scanf ("%u%u", &n, &m);
      if (n == 0 && m == 0)
	break;
      for (v = verts; v < verts + n; v++)
	v->deg = 0;
      while (m != 0)
	{
	  unsigned a, b;
	  
	  m--;
	  scanf ("%u%u", &a, &b);
	  add_edge (verts + a, verts + b);
	  add_edge (verts + b, verts + a);
	}
      gen++;
      dfs_index = 0;
      max_deg = 0;
      comps = 0;
      for (v = verts; v < verts + n; v++)
	{
	  if (v->gen != gen)
	    {
	      walk (v);
	      comps++;
	    }
	}
      /* printf ("COMPS %u, DEG %u\n", comps, max_deg); */
      if (max_deg != 0)
	comps += max_deg - 1;
      printf ("%u\n", comps);
    }
  return EXIT_SUCCESS;
}