#include <bits/stdc++.h>

using namespace std;

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

bitset <100001> viz;

int n, m, i, j, nrcmp;

vector <int> v[100001];

void DFS (int nod)
{
    vector<int> :: iterator i;
    int curent;
    for (i=v[nod].begin(); i!=v[nod].end(); i++)
    {
        curent = *i;
        if (viz[curent] == 0)
        {
            viz[curent] = 1;
            DFS(curent);
        }
    }
}

int main()
{
    fin >> n >> m;
    while(m--)
    {
        fin >> i >> j;
        v[i].push_back(j);
        v[j].push_back(i);
    }
    for (i=1; i<=n; i++)
        if (viz[i] == 0)
        {
            viz[i] = 1;
            nrcmp++;
            DFS(i);
        }
    fout << nrcmp;
    return 0;
}