#include <bits/stdc++.h>

using namespace std;
ifstream f ("dfs.in");
ofstream g ("dfs.out");
bool a[100002];
int n,m,i,x,y,mc;
vector <int> G[100001];
void dfs (int nod)
{
    int i;
    a[nod] = true;
    for (i = 0; i < G[nod].size(); i++)
    {
        if (!a[G[nod][i]])
        {
            dfs (G[nod][i]);
        }
    }
}
int main()
{
    mc = 0;
    f >> n >> m;
    for (i = 1; i <= m; i++)
    {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for (i = 1; i <= n; i++)
    {
        if (!a[i])
        {
            mc ++;
            dfs(i);
        }
    }
    g << mc << '\n';
    return 0;
}