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

void dfs(int nod)
{
    viz[nod] = 1;
    for(int i = 0; i < v[nod].size(); i++)
    {
        int vecin = v[nod][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}

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 ans = 0;
    for(int i = 1; i <= n; i++)
    {
        if(!viz[i])
        {
            dfs(i);
            ans++;
        }
    }
    out << ans << "\n";
    return 0;
}