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

using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");

const int NMax = 1e5 + 5;

int N,M,sol;
bool viz[NMax];
vector<int> v[NMax];

void dfs(int nod) {
    viz[nod] = true;

    for (int k=0;k < v[nod].size();++k) {
        int next = v[nod][k];
        if (!viz[next]) {
            dfs(next);
        }
    }
}

int main() {
    in>>N>>M;
    for (int i=1;i<=M;++i) {
        int x,y;
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (int i=1;i<=N;++i) {
        if (viz[i]) {
            continue;
        }
        ++sol;
        dfs(i);
    }

    out<<sol<<'\n';
    in.close();out.close();
    return 0;
}