#include <bits/stdc++.h>

using namespace std;

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

int n,m;
vector<int>a[100005];

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

bool viz[100005];


void dfs(int nod)
{
    viz[nod] = true;
    for(int i = 0; i < a[nod].size(); i++)
    {
        int vecin = a[nod][i];
        if(viz[vecin] == false)
            dfs(vecin);
    }
}

int main()
{
    int i,ncc = 0;
    citire();
    for(i = 1; i <= n; i++)
    {
        if(viz[i] == false)
        {
            dfs(i);
            ncc++;
        }
    }
    out << ncc;
    return 0;
}