#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5;
bool viz[NMAX + 5];
int dist[NMAX + 5], ans;

vector<int> adj[NMAX + 5];


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

int main(){
    int n, m;
    fin>>n>>m;
    for(int i = 1; i <= m; i++){
        int x, y;
        fin>>x>>y;
        adj[x].push_back(y);
        adj[y].push_back(x); 
    }
    for(int i = 1; i <= n; i++){
        if(!viz[i]){
            dfs(i);
            ans++;
        }
    }
    fout<<ans<<"\n";
    return 0;   
}