#include <iostream>
#include <fstream>
#include <list>

using namespace std;

void dfs(list<int> *L,int x[], int i) {
    x[i]=1;
    for(list<int>::iterator it=L[i].begin(); it!=L[i].end();it++) {
        if(x[*it] == 0) {
            dfs(L, x, *it);
        }
    }
}

int main()
{
    ifstream f("dfsinput.in");
    ofstream g("dfsoutput.out");
    int m,n;
    f>>n>>m;
    int p,h;
    int k=0;
    list<int> *Liste= new list<int>[n+1];

    while(m--){
        f>>p>>h;
        Liste[p].push_back(h);
        Liste[h].push_back(p);
    }
    f.close();

    int x[n+1]={0};

    for(int i=1;i<n+1;i++) {
        if(x[i]==0) {
            dfs(L, x, i);
            k++;
        }
    }
    g<<k;
    g.close();

    return 0;
}