#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

#define nrmax 100002

vector <int> g[nrmax];
int v[nrmax];

void dfs(int x){
    v[x] = 1;
    int lim = g[x].size();
    for(int i = 0; i<lim; i++) {
        if(v[g[x][i]] == 0) dfs(g[x][i]);
    }
}

int main()
{

    int compConex = 0, m, n, i, x, y;
    ifstream f("dfs.in");
    ofstream p("dfs.out");
    f>>n>>m;
    for(i=0; i<m; i++){
        f>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
   }

   for(i=1; i<=n; i++)
        if(v[i] == 0){
            dfs(i);
            compConex++;
        }

    p<<compConex;

   return 0;

}