# include <cstdio>
# include <vector>
# define Nmax 100002
using namespace std;
vector<long> a[Nmax];
long n,m,x,y,nr,viz[Nmax];
void dfs(long p)
{long q;
 viz[p]=1;
 for(long i=0; i<a[p].size(); ++i ) 
	 {q=a[p][i];
	  if(!viz[q]) dfs(q);
	 }
}
int main()
{freopen ("dfs.in", "r", stdin); freopen ("dfs.out", "w", stdout);
 scanf ("%ld%ld", &n, &m);
 for(long i=1; i<=n; ++i ) viz[i]=0;
 for(long i = 1; i <= m; ++i) {scanf ("%ld%ld", &x, &y); a[x].push_back(y); a[y].push_back(x);}
 for(long i=1; i<=n; ++i ) 
	 {if(!viz[i]) 
		  {nr++; dfs(i);}
	 }
 printf("%d\n",nr); return 0;
}