#include <iostream>
#include <math.h>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <iomanip>
#include <stdlib.h>
#include <fstream>
#include <algorithm>
#include <string>
#include <set>
#include <cstring>
#define INF 1e9
using namespace std;
#define NMAX 100001
ifstream f("dfs.in");
ofstream g("dfs.out");
vector<int> G[NMAX];
bool viz[NMAX];
int contor ;
void dfs(int nod)
{
    viz[nod] = 1;
    for(vector<int>::iterator it = G[nod].begin(); it!= G[nod].end() ; it++)
    {
        if(!viz[*it])
        {
            dfs(*it);
        }
    }
}
int main() {
    int n , m;
    f>>n>>m;
    for(int i=1;i<=m;i++)
    {
        int a , b;
        f>>a>>b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    for(int i=1;i<=n;i++)
    {
        if(!viz[i])
        {
            contor++;
            dfs(i);
        }
    }
    g<<contor;
    return 0;
}