#include <fstream>
#include <vector>

using namespace std;

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

const int NMAX = 100005;

int n, m;

bool vis[NMAX];

vector<int> g[NMAX];

void dfs(int nod)
{
    vis[nod] = true;
    for(int i = 0; i < g[nod].size(); i++)
    {
        int vecin = g[nod][i];
        if(vis[vecin] == false)
            dfs(vecin);
    }

}

int main()
{
    int k = 0;
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(int i = 1; i <= n; i++)
    {
        if(vis[i] == false)
        {
            dfs(i);
            k++;
        }
    }
    fout << k;
    return 0;
}