#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5 + 7;

vector<vector<int>> v(NMAX);
vector<int> comp(NMAX);
int n, m;

void dfs(int nod, int nr)
{
    comp[nod] = nr;

    for(auto it : v[nod])
    {
        if(comp[it] == 0)
        {
            dfs(it, nr);
        }
    }
}

int main()
{
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;

        v[x].push_back(y);
        v[y].push_back(x);
    }

    int nr = 0;
    for(int i = 1; i <= n; i++)
    {
        if(comp[i] == 0)
        {
            nr++;
            dfs(i, nr);
        }
    }

    fout << nr;

    return 0;
}