#include <iostream>
#include <fstream>
#include <bitset>
#include <vector>
#include <queue>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int maxn = 100005;
vector <int> v[maxn];
bitset <maxn> viz;
queue <int> q;

void bfs(int st)
{
    viz[st] = 1;
    q.push(st);
    while(!q.empty())
    {
        int nod = q.front();
        q.pop();
        for(auto it : v[nod])
        {
            if(!viz[it])
            {
                viz[it] = 1;
                q.push(it);
            }
        }
    }
}

int main()
{
    int n, m;
    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);
    }
    int conexe = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            conexe++;
            bfs(i);
        }
    }
    out << conexe << "\n";
    return 0;
}