//
//  dfs.cpp
//  Parcurgerea DFS
//
//  Created by Andrei Constantinescu on 2/26/13.
//  Copyright (c) 2013 Andrei Constantinescu. All rights reserved.
//
#define dim 100001

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

vector<long> vec[dim];
long m,n,k, v[dim];

void dfs(long nod) {
    v[nod]=1;
    for(long i=0;i<vec[nod].size();i++)
        if(v[vec[nod][i]]==0)
            dfs(vec[nod][i]);
}

int main() {
    ifstream f ("dfs.in", ios::in);
    ofstream g ("dfs.out", ios::out);
    f>>n>>m;
    
    for(long i=1;i<=m;i++) {
        long x,y;
        f>>x>>y;
        vec[x].push_back(y);
        vec[y].push_back(x);
    }
    
    for(long i=1;i<=n;i++)
        if(v[i]==0) {
            dfs(i);
            k++;
        }
    
    g<<k;
    f.close();
    g.close();
    return 0;
}