#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 o("dfsoutput.out");
    int a,b;
    f>>b>>a;
    int c,d;
    int k = 0;
    list<int> *L = new list<int>[b+1];

    while (a--){
        f>>c>>d;
        L[c].push_back(d);
        L[d].push_back(c);
    }
    f.close();

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

    return 0;
}