#include <bits/stdc++.h>
using namespace std;
#define ll long long
const int MAX = 100005;

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

bool visited[MAX];
int N, M;
vector<int> Muchii[MAX];

void dfs(int Node){
        visited[Node]=true;
        for(int i=0; i<Muchii[Node].size(); i++)
                if(!visited[Muchii[Node][i]])
                        dfs(Muchii[Node][i]);
}

void solve(){
        fin >> N >> M;
        for(int i=1; i<=M; i++){
                int x, y;
                fin >> x >> y;
                Muchii[x].push_back(y);
                Muchii[y].push_back(x);
        }
}


int main(){
        solve();
        int insule=0;
        for(int i=1; i<=N; i++)
                if(!visited[i]){
                        insule++;
                        dfs(i);
        }
        fout << insule;
return 0;
}