#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
#include <string.h>
#define nmax 100005

using namespace std;

vector<int> G[nmax];
queue<int> Q;
int viz[nmax], head, n, m, x, y, comps;

void build(){
    ifstream f("dfs.in");
    f >> n >> m;
    for(int i=1; i<=m; i++){
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void bfs(){
    int i;
    while(!Q.empty()){
        int x = Q.front();
        Q.pop();
        viz[x] = 1;

        for(i = 0; i < int(G[x].size()); i++){
            if(!viz[G[x][i]]){
                Q.push(G[x][i]);
                viz[G[x][i]] = 1;
            }
        }
    }
}

int main()
{
    ofstream g("dfs.out");
    build();
    for(int i=1; i<=n; i++)
        if(!viz[i]){
            comps++;
            Q.push(i);
            bfs();
        }
    g << comps;
    return 0;
}