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

const int NMAX=100006;
vector<vector<int>>graf;
bitset<NMAX>viz;
void dfs(int nod)
{
    viz[nod]=1;
    for(int urm:graf[nod])
        if(!viz[urm])
            dfs(urm);
}
int main()
{   int n,m,x,y,ct=0;
    fin>>n>>m;
    graf.assign(n+1,vector<int>());
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

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