#include <bits/stdc++.h>

using namespace std;

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

vector <int> v[100005];
int viz[100005];
int n, m, ans;

void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0; i<v[nod].size(); i++)
        if(!viz[v[nod][i]] == 0)
            dfs(v[nod][i]);
}

int main()
{
    int x, y;
    f>>n>>m;

    for(int i=1; i<=m; i++)
    {

        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(int i=1; i<=n; i++)

    {
        if(viz[i] == 0)
        {
            dfs(i);
            ans++;
        }
    }
    g<<ans;

    return 0;
}