#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m;
int viz[100005];
vector < int > muchii[100005];
int insule = 0;
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0; i<muchii[nod].size(); i++)
    {
        int vecin=muchii[nod][i];
        if(!viz[vecin])
            dfs(vecin);
    }
}
void citire()
{
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        fin>>x>>y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }

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