#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

vector <vector <int>> G;
int viz[100001];

void DFS(int node){

    viz[node] = true;

    for(int vec : G[node]){
        if(!viz[vec]){
            DFS(vec);
        }
    }

}

int main()
{
    int n, m;
    fin>>n>>m;
    G.resize(n + 1);

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

    int cnt = 0;
    for(int i = 1; i <= n; i++){
        if(!viz[i]){
            DFS(i);
            cnt++;
        }
    }

    fout<<cnt;

    return 0;
}