#include <bits/stdc++.h>
using namespace std;

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

vector<int> g[100005];
int n, m;
int v[100005];


void citire() {
    fin >> n >> m;
    for(int i = 1; i <= m; i++) {
        int a, b;
        fin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
}

void dfs(int x, int cc) {
    v[x] = cc;
    for(int i = 0; i < g[x].size(); i++)
        if(!v[g[x][i]])
            dfs(g[x][i], cc);
}

void solve() {
    int nr = 0;
    for(int i = 1; i <= n; i++)
        if(!v[i])
            dfs(i, ++nr);
    fout << nr;
}

//void afis() {
//    for(int i = 1; i <= n; i++)
//        fout << dist[i] << ' ';
//}

int main() {
    citire();
    solve();
    //afis();
}