#include <bits/stdc++.h>

using namespace std;

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

int n,m,viz[100003];
vector<int>h[100003];

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

void DFS(int nod)
{
    viz[nod] = 1;
    for(auto i : h[nod])
        if(!viz[i])
            DFS(i);
}

void Rezolvare()
{
    int i,sol;
    sol = 0;
    for(i=1;i<=n;i++)
        if(!viz[i])
        {
            DFS(i);
            sol++;
        }
    fout<<sol<<"\n";
}

int main()
{
    Citire();
    Rezolvare();

    fin.close();
    fout.close();
    return 0;
}