#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int nmax = 10e5;
int n, m;
vector< int > adj[nmax + 1];

void citire() {
    fin >> n >> m;
    for(int i = 1; i<= m; i ++) {
        int x, y;
        fin >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
}

int viz[nmax + 1];
void dfs(int u) {
    viz[u] = 1;
    for (auto &v : adj[u]) {
        if (viz[v] == 1)
            continue;
        dfs(v);
    }
}

int main() {
    citire();

    int sol = 0;
    for(int i = 1; i <= n; i ++) {
        if(viz[i] == 0) {
            sol = sol + 1;
            dfs(i);
        }
    }
    fout << sol;
    exit(0);
}