#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int nlim = 100005;

int n, m, conex_components;
bool visited[nlim];

vector <int> edges[nlim];

void DFS(int node){
    visited[node] = true;
    for(int i = 0; i < edges[node].size(); i++){
        int adj = edges[node][i];
        if(!visited[adj])
            DFS(adj);
    }
}

void read(){
    fin >> n >> m;
    for(int i = 1; i <= m; i++){
        int x, y;
        fin >> x >> y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
    for(int i=1;i<=n;i++){
        if(!visited[i])
            conex_components++;
        DFS(i);
    }
    fout<<conex_components;
}

int main(){
    read();
}