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

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


vector<int> adj[100005];
unordered_map<int,bool> visited;


void addEdge(vector<int> adj[], int u, int v)
{
    adj[u].push_back(v);
    adj[v].push_back(u);
    //cout<<u<<" "<<v<<endl;
}

void DFS(int v)
{
    visited[v] = true;
    //cout << v << " ";
    for (int i = 0; i < adj[v].size(); ++i)
        if (!visited[adj[v][i]])
            DFS(adj[v][i]);
}

int main()
{
    int n,m,prev,cur;
    in>>n;
    in>>m;
    for(int i=1; i<=m; i++)
    {
        int a,b;
        in>>a>>b;
        addEdge(adj,a,b);
    }
    int ct=0;
    for(int i=1; i<=n; i++)
    {
        if(visited[i] == 0)
        {
            DFS(i);
            ct++;
        }

    }
    out<<ct;


    return 0;
}