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

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

int n, m, visited[100001];
vector <int> edges[100001];
queue <int> q;

void DFS(int nod) {
    visited[nod] = 1;
    for(unsigned int i = 0; i < edges[nod].size(); i++) {
        int neighbour = edges[nod][i];
        if(visited[neighbour] == 0)
            DFS(neighbour);
    }
}

int conexComp() {
    int conx = 0;
    for(int i = 1; i <= n; i++) {
        if(visited[i] == 0) {
            conx += 1;
            DFS(i);
        }
    }
    return conx;
}

void Read() {
    fin>>n>>m;
    int x, y;
    for(int i = 1; i <= m; i++) {
        fin>>x>>y;
        edges[x].push_back(y);
        edges[y].push_back(x);
    }
}


int main() {
    Read();
    fout<<conexComp();
    return 0;
}