#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

using namespace std;

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

int n, m, i, x, y, nr_comp;
bool viz[100005];
vector <int> v[100005];

void dfs(int nod)
{
    viz[nod] = 1;
    for(vector <int> :: iterator it = v[nod].begin(); it != v[nod].end(); ++ it)
    {
        if(!viz[*it])
        {
            dfs(*it);
        }
    }
}
int main()
{
    f >> n >> m;
    for(i = 1; i <= m; ++ i)
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i = 1; i <= n; ++ i)
       {
           if(!viz[i])
           {
               dfs(i);
               nr_comp ++;
           }
       }
    g << nr_comp;
    return 0;
}