#include <bits/stdc++.h>


using namespace std;

int n,m,x,y,viz[100000],k;
vector<int>v[100005];



void dfs(int nod){
	viz[nod]=1;

	
	for(int i =0;i<(int)v[nod].size();i++)
	if(!viz[v[nod][i]])dfs(v[nod][i]);	
		
}


ifstream in("dfs.in");
ofstream out("dfs.out");

int main(){
	in >> n >> m;
for(int i=1;i<=m;i++){
	in >>x>>y;
	v[x].push_back(y);
	v[y].push_back(x);
}
for(int i=1;i<=n;i++){
	if(!viz[i]){
		k++;
		dfs(i);
		
	}
		
}

out << k;

return 0;
}