#include <fstream>
#include <vector>
#define InFile  "dfs.in"
#define OutFile "dfs.out"
#define MAX 100001

using namespace std;

void DFS (unsigned int node);

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

vector < unsigned int > G[MAX];
bool used[MAX];
unsigned int i, j;

unsigned int cnt;

int main ()
{
    ifstream fin  (InFile);
    ofstream fout (OutFile);
    fin >> N >> M;
    for (i=1; i<=M; i++)
    {
        fin >> X >> Y;
        G[X].push_back(Y);
        G[Y].push_back(X);
    }
    for (i=1; i<=N; i++)
        if (!used[i])
        {
            DFS(i);
            cnt++;
        }
    fout << cnt;
    fin.close();
    fout.close();
    return 0;
}

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