#include <iostream>
#include <limits.h>
#include <cmath>
#include <string>
#include <stdio.h>
#include <algorithm>
#include <stdlib.h>
#include <vector>
#include <stack>
#include <map>
#include <fstream>

#define nMax 100009

using namespace std;

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

int i,j,n,m,x,y,viz[nMax];
vector <int> v[nMax];

void dfs(int nod)
{
    viz[nod] = 1;
    int i;
    for(i=0; i < v[nod].size(); i++)
        if ( viz[ v[nod][i] ] == 0 )
            dfs ( v[nod][i] );
}

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

    int conex = 0;

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

    return 0;
}