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

using namespace std;

#define Nmax 100005

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int N, M, viz[Nmax], comp;
vector <int> v[Nmax];

void dfs(int node) {
    viz[node] = 1;
    vector <int> :: iterator it;
    for(it = v[node].begin(); it != v[node].end(); ++it)
        if(!viz[*it])
            dfs(*it);
}

int main() {
    fin >> N >> M;
    int x, y;
    while(M--) {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i = 1; i <= N; i++)
        if(!viz[i]) {
            comp++;
            dfs(i);
        }
    fout << comp;
}