#include <bits/stdc++.h>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

const int MAXN=200010;

vector <int> g[MAXN];
bool visit[MAXN];
int n,m;

void dfs (int nod){
    visit[nod]=1;
    for (int i=0;i<g[nod].size ();++i)
        if (visit[g[nod][i]]==0)
            dfs (g[nod][i]);
}

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

    int rez=0;
    for (int i=1;i<=n;++i){
        if (visit[i]==0){
            rez++;
            dfs (i);
        }
    }
    fout <<rez;
    fin.close ();
    fout.close ();
    return 0;
}