#include <fstream>
#include <vector>

using namespace std;

vector<int> G[100010];
int viz[100010];
int n , m , x , y;
int cont = 0;
int comp[100010];

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

void DFS(int nod , int nr)
{
    viz[nod] = 1;
    comp[nod] = nr;
    for(auto it:G[nod])
        if(!viz[it])
            DFS(it , nr);
}

int main()
{
    fin >> n >> m;
    for(int i = 1 ; i <= m ; i++){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(int i = 1 ; i <= n ; ++i){
        if(!viz[i]){
            cont++;
            DFS(i , cont);
        }
    }

    fout << cont;
    return 0;
}