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

#define NMAX 100000 // o suta de mii

using namespace std;

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

bool viz[NMAX + 1];
vector <int> G[NMAX + 1];

void DFS(int node){
    viz[node] = 1;

    for(int i = 0; i < G[node].size(); i++){
        int vec = G[node][i];

        if(!viz[vec]){
            DFS(vec);
        }
    }
}

int main()
{
    int N, M;
    fin >> N >> M;

    for(int i = 1; i <= M; i++){
        int x, y;
        fin >> x >> y;

        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    fout << nrConexe;
    return 0;
}