#include <fstream>
#include <vector>
using namespace std;

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

void Read();
void DFS(int node);
void WriteV();

vector<vector<int> > G;
vector<bool> V;
int n, m, ctr;

int main()
{
    Read();

    for (int i = 1; i <= n; ++i)
        if ( !V[i] )
            DFS(i), ctr++;

    fout << ctr << '\n';

    fin.close();
    fout.close();
    return 0;
}

void DFS(int node)
{
    if ( !V[node] )
    {
        V[node] = true;
        for (unsigned int i = 0; i < G[node].size(); ++i)
            DFS(G[node][i]);
    }
}

void Read()
{
    fin >> n >> m;
    G.resize(n+1);
    V.resize(n+1);
    int x, y;
    for (int i = 1; i <= m; ++i)
    {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}