#include <fstream>
#include <vector>
#include <bitset>
#define Nmax 100009

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m,x,y,sol;
bitset <Nmax> viz;
vector <int> G[Nmax],cc;

void DFS(int node)
{
    cc.push_back(node);
    viz[node]=1;
    for (auto x : G[node])
        if (viz[x]==0) DFS(x);
}

int main()
{
    f>>n>>m;
    for (int i=1; i<=m; ++i) {
        f>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (int i=1; i<=n; ++i)
        if (viz[i]==0) {
            ++sol;
            DFS(i);
            //for (auto x:cc)
                //g<<x<<' ';
            //g<<'\n';
            cc.clear();
        }
    g<<sol<<'\n';
    f.close(); g.close();
    return 0;
}