#pragma GCC optimize("O3")

#include <iostream>
#include <bits/stdc++.h>
#define pb push_back

using namespace std;

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

vector < list < int > > L;
int viz[100010];

void DFS(int s)
{
    viz[s] = 1;
    for (int i:L[s])
        if (!viz[i])
            DFS(i);
}

int main()
{
    ios_base::sync_with_stdio(0);
    fin.tie(0); fout.tie(0);

    int n,m,x,y,nr = 0;
    fin >> n >> m;
    L.resize(n+1);
    for (int i = 0; i < m; i++)
    {
        fin >> x >> y;
        L[x].pb(y);
        L[y].pb(x);
    }
    for (int i = 1; i <= n; i++)
        if(!viz[i])
        {
            DFS(i);
            nr++;
        }
    fout << nr;
    return 0;
}