#include<stdio.h>
#include<list>
#define dim 100010
using namespace std;

int n,m,x,y,i,Fr[dim],nr;
list<int>L[dim];
list<int>::iterator it;
FILE*f=fopen("dfs.in","r");
FILE*g=fopen("dfs.out","w");

void dfs(int z){
	Fr[z]=1;
	list<int>::iterator d;
	for(d=L[z].begin();d!=L[z].end();d++){
		if(!Fr[*d]) dfs(*d);
	}
}

int main(){
	fscanf(f,"%d%d",&n,&m);
	for(i=1;i<=m;i++){
		fscanf(f,"%d%d",&x,&y);
		L[x].push_back(y);
		L[y].push_back(x);
	}
	/*for(i=1;i<=n;i++){
		for(it=L[i].begin();it!=L[i].end();it++){
			fprintf(g,"%d ",*it);
		}
		fprintf(g,"\n");
	}*/
	for(i=1;i<=n;i++){
		if(!Fr[i]){
			dfs(i);
			nr++;
		}
	}
	fprintf(g,"%d",nr);
	return 0;
}