#include<iostream>
#include<vector>
using namespace std;

const int NMAX=1e5;
int n,m,k;
vector<int> g[NMAX+1];
bool viz[NMAX+1];

void dfs(int nod){
	viz[nod]=1;
	for(auto vec:g[nod]){
		if(!viz[vec]){
			dfs(vec);
		}
	}
}

int main(){
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	cin>>n>>m;
	while(m--){
		int x,y;
		cin>>x>>y;
		g[x].push_back(y);
		g[y].push_back(x);
	}
	for(int i=1;i<=n;++i){
		if(!viz[i]){
			dfs(i);
			k++;
		}
	}
	cout<<k;
}