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


ifstream f("dfs.in");
ofstream f2("dfs.out");

int viz[100001], n, m, s, x, y, plecare, i;

vector <int> listadeAdiacenta[100001];

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

    for(i = 1; i <= listadeAdiacenta[plecare].size(); i++){
        int vecin = listadeAdiacenta[plecare][i];
        if(viz[vecin] == 0){
            DFS(vecin);
        }
    }

}


int main()
{
    f >> n >> m;
    int insule = 0;

    for(i = 1; i <= n; i++){
        viz[i] = 0;
    }

    for(i = 1; i <= m; i++){
        f >> x >> y;
        listadeAdiacenta[x].push_back(y);
        listadeAdiacenta[y].push_back(x);
    }
    listadeAdiacenta[i][m];

    for(i = 1; i <= n; i++){
        if(viz[i] == 0){
            insule++;
            DFS(i);
        }
    }
    f2 << insule;

    return 0;
}