#include<fstream>
#include<list>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
list<int>l[100005];
bool viz[100005];
int n, m, nr_comp;
void citire()
{
    f >> n >> m;
    int x, y;
    while(f >> x >> y)
    {
        l[x].push_back(y);
        l[y].push_back(x);
    }
}
void dfs(int nc)
{
    list<int> :: iterator it;
    for(it = l[nc].begin(); it != l[nc].end(); it++)
        if(!viz[*it])
        {
            viz[*it] = 1;
            dfs(*it);
        }
}
void solve()
{
    int i;
    for(i = 1; i <= n; i++)
        if(!viz[i]){
            nr_comp++;
            dfs(i);
        }
    g << nr_comp;
}
int main(){
    citire();
    solve();
}