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

using namespace std;

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

int n, m, cont;
vector<int> nod[100009];
int viz[100009];

void dfs(int n){
    viz[n] = 1;
    for(auto i : nod[n]){
        if(viz[i] == 0){
            dfs(i);
        }
    }
}

int main()
{
    int x, y;
    f>>n>>m;
    for(int i = 1; i <= m; i++){
        f>>x>>y;
        nod[x].push_back(y);
        nod[y].push_back(x);
    }
    for(int i = 1; i <= n; i++){
        if(viz[i] ==0){
            cont++;
            dfs(i);
        }
    }
    g<<cont;
    return 0;
}