#include <fstream>
#include <vector>
#define N 100005
using namespace std;

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

int x, y, n, m, compConvexe;
bool viz[N];
vector< vector<int> > graf(N);

void dfs(int nod){
    viz[nod]=1;

    for(int i=0; i<graf[nod].size(); ++i)
        if(!viz[graf[nod][i]]) dfs(graf[nod][i]);
}

int main()
{
    in>>n>>m;

    for(int i=1; i<=m; ++i){
        in>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    for(int i=1; i<=n; ++i){
        if(!viz[i]){
            compConvexe++;
            dfs(i);
        }
    }

    out<<compConvexe;

    in.close();
    out.close();
    return 0;
}