#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

#define MAX 200000

vector < int > v[MAX];

unsigned n, m, x, y, viz[MAX], k;

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

void dfs(unsigned nod)
{
    viz[nod] = 1;
    for(int i = 0; i < v[nod].size(); i++)
        if(viz[v[nod][i]] == 0)
            dfs(v[nod][i]);
}
int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            dfs(i);
            k++;
        }
    }
    fout << k;
    return 0;
}