#include <cstdio>
#include <vector>

using namespace std;

#define file_in "dfs.in"
#define file_out "dfs.out"

int N,M;
int A,B;
int i,ans;
vector<int> G[101000];
int viz[101000];

void dfs(int nod){
	
	vector<int> :: iterator it;
	
	viz[nod]=1;
	
	for (it=G[nod].begin();it!=G[nod].end();++it)
		 if (!viz[*it])
			 dfs(*it);
}

int main(){
	
	freopen(file_in,"r",stdin);
	freopen(file_out,"w",stdout);
	
	scanf("%d %d", &N,&M);
	while(M--){
		scanf("%d %d", &A, &B);
		
		G[A].push_back(B);
		G[B].push_back(A);
	}
	
	for (i=1;i<=N;++i)
		 if (!viz[i]){
			 ans++;
			 dfs(i);
		 }
		 
	printf("%d\n", ans);

	return 0;
	
}