#include <bits/stdc++.h>

using namespace std;

const int kNmax = 1e5 + 5;

vector<int> adj[kNmax];
bool visited[kNmax];

void dfs(int source) {
    stack<int> s;
    s.push(source);
    visited[source] = true;
    while(!s.empty()) {
        int nod = s.top();
        s.pop();
        for(auto vecin : adj[nod]) {
            if(!visited[vecin]) {
                s.push(vecin);
                visited[vecin] = true;
            }
        }
    }
}

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

    int n, m;
    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 nr_comp = 0;
    for(int i = 1; i <= n; i++) {
        if(!visited[i]) {
            dfs(i);
            nr_comp++;
        }
    }

    fout<<nr_comp<<endl;

    return 0;
}