#include <fstream>
#include <vector>

using namespace std;

void DFS (unsigned int node);

unsigned int N, M;
unsigned int X, Y;

vector <unsigned int> v[100001];
bool seen[100001];
unsigned int i;

unsigned int sol;

int main ()
{
    ifstream fin ("dfs.in");
    fin >> N >> M;
    for (i=1; i<=M; i++)
    {
        fin >> X >> Y;
        v[X].push_back(Y);
        v[Y].push_back(X);
    }
    fin.close();
    for (i=1; i<=N; i++)
        if (!seen[i])
        {
            DFS(i);
            sol++;
        }
    ofstream fout ("dfs.out");
    fout << sol;
    fout.close();
    return 0;
}

void DFS (unsigned int node)
{
    vector <unsigned int> :: iterator i;
    seen[node] = 1;
    for (i=v[node].begin(); i<v[node].end(); i++)
        if (!seen[*i])
            DFS(*i);
}