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

using namespace std;

ofstream out("dfs.out");

const int N = 100001;
vector <int> a[N];
int n;
bool viz[N];

void citire(){
    ifstream in("dfs.in");
    int m,x,y;
    in >> n >> m;
    for(int i = 0;i < m;i++){
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    in.close();
}

void dfs(int x){
    viz[x] = true;
    for(int i = 0;i < a[x].size() ;i++){
        int y = a[x][i];
        if(!viz[y]){
            dfs(y);
        }
    }
}

int main()
{   int nr = 0;
    citire();
    for(int i = 1; i <= n;i++){
        if(viz[i] == false) {
            dfs(i);
            nr++;
        }
    }
    out << nr;
    return 0;
}