#include <bits/stdc++.h>

using namespace std;

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

const int N = 100005;

vector <int> edges [N];

int n, m, x, y, comp=0;

bool visited [N];

void dfs(int nod){
    visited[nod]=true;
    for(auto it:edges[nod])
        if(!visited[it])
            dfs(it);
}

int main(){
    fin>>n;
    fin>>m;
    for(int i=0; i<m; i++){
        fin>>x>>y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
    for(int i=1; i<=n; i++){
        if(visited[i]==false){
             dfs(i);
             comp++;
        }
    }
    fout<<comp;
}