#include <bits/stdc++.h>

using namespace std;

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

int k;
vector <int> g[100100];
bool v[100100];

void dfs(int x){
	v[x] = 1;
	
	for(int i = 0; i<g[x].size(); i++){
		if(!v[g[x][i]])
			dfs(g[x][i]);
	}
}

int n, m;
int main(){
	k=0;
	fin >>n;
	fin >>m;
	int x,y;
	for (int i=1;i<=m;i++){
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for (int i=1;i<=n;i++){
        if (!v[i]) {
            k++;
            dfs(i); 
        }
    }
	
	fout << k;
	
	
}