#include <stdio.h>
 
int a[1005][1005], n, m, viz[1005], cnt;

void citire()
{
freopen("dfs.in","r",stdin);
freopen("dfs.out","w",stdout);
scanf("%d %d",&n,&m);
int i, x, y;
for (i = 1; i <= m; i++)
{
scanf("%d %d",&x,&y);
a[x][y] = a[y][x] = 1;
}
}
 
void DFS(int nod)
{
int i;
viz[nod] = 1;
for (i = 1; i <= n; i++) if (!viz[i] && a[nod][i]) DFS(i);
}  
 
int main()
{
citire();
int i;
for (i = 1; i <= n; i++) if (!viz[i]) { cnt++; DFS(i); }
printf("%d\n",cnt);
return 0;
}