#include <fstream>
#include <vector>

using namespace std;

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

vector<vector <int>>edges;
vector<int>viz;
int n, nr=0;

void read()
{
    int m;
    fin>>n>>m;
    edges.resize(n+1);
    viz.resize(n+1);
    for (int i=0; i<m; i++)
    {
        int a, b;
        fin>>a>>b;
        edges[a].push_back(b);
        edges[b].push_back(a);
    }
}

void dfs (int node)
{
    viz[node]=true;
    for (auto next:edges[node])
    {
        if (viz[next])
            continue;
        dfs(next);
    }
}

int main()
{
    read();
    /*
    for (int i=1; i<=n; i++)
    {
        fout<<i<<" ";
        for (int j=0; j<edges[i].size(); j++)
        {
            fout<<edges[i][j]<<" ";
        }
        fout<<"\n";
    }
    */
    for (int i=1; i<=n; i++)
    {
        if (!viz[i])
        {
            dfs(i);
            nr++;
        }
    }
    fout<<nr;
    return 0;
}