#include <iostream>
#include <vector>
#include <queue>
#include <fstream>
using namespace std;

vector <int> v[10000];
queue <int> q;
queue <int> p;
int viz[100000];
void DF(int x)
{
        int j;
        viz[x]=1;
        for(j=0;j<v[x].size();j++)
            if(viz[v[x][j]]==0)
                DF(v[x][j]);
}
int main()
{
    int m,n,s,e,b,k=0;
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    f>>n>>m;
    for(s=1;s<=m;s++)
    {
        f>>e>>b;
        v[e].push_back(b);
        v[b].push_back(e);
    }
    for(s=1;s<=n;s++)
        if(!viz[s])
        {
            DF(s);
            k++;
        }
    g<<k;
    f.close();
    g.close();
    return 0;
}