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

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

vector<int> L[100001];
int vis[100001];

void dfs(int node){
    vis[node] = 1;
    for(auto vec : L[node]){
        if(vis[vec] == 0){
            dfs(vec);
        }
    }
}

int main(){
    int n,m;
    fin >> n >>m;
    for(int i=1; i<=m;i++){
        int a,b;
        fin>>a>>b;
        L[a].push_back(b);
        L[b].push_back(a);

    }
    int nr = 0;
    for(int i=1;i<=n;i++){
        if(vis[i]==0){
            nr++;
            dfs(i);
        }
    }
    fout<< nr<<"\n";
    return 0;
}