#include <iostream>
#include <vector>
using namespace std;
 
const int MAXN=500005;
 
vector<int> adj[MAXN];
int col[MAXN];
 
void dfs(int v, int b){
	col[v]=b;
	for(int u: adj[v]){
		if(col[u]==0)
		dfs(u, b);
	}
}
 
 
 
 
 
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
int n,m;
cin>>n>>m;
for(int i=0; i<m; i++){
	int a,b;
	cin>>a>>b;
	adj[a].push_back(b);
	adj[b].push_back(a);
}
int ile=0;
for(int i=1; i<n+1; i++){
	if(col[i]==0){
		ile++;
		dfs(i, ile);
	}
}
 
cout<<ile;
 
	return 0;
}

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3  6
2 3
4 6
4 2