#include <fstream>
#include <vector>
#include <queue>
#include <bitset>
using namespace std;

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

vector < vector <int> > g;
bitset <100005> viz;
queue <int> q;
int n, m, st;

void citire()
{
    int x, y;
    fin>>n>>m;
    g = vector < vector <int> > (n+2);
    for (int i=1; i<=m; ++i)
    {
        fin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

void dfs(int x)
{
    viz[x]=1;
    for (auto y:g[x])
        if (!viz[y]) dfs(y);
}

void solve()
{
    int ct=0;
    for (int i=1; i<=n; ++i)
        if (!viz[i]) {dfs(i);ct++;}
    fout<<ct;
}


int main()
{
    citire();
    solve();
    return 0;
}