#include <iostream>
#include <fstream>
#include <vector>
#define NMAX 100005
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int viz[NMAX],n,m,nrcomp;
vector <int> muchie[NMAX];
void read()
{
    f>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        f>>x>>y;
        muchie[x].push_back(y);
        muchie[y].push_back(x);
    }
    f.close();
}
void dfs(int x)
{
    viz[x]=1;
    for(int i=0; i<muchie[x].size(); i++)
        if(viz[muchie[x][i]]==0)
            dfs(muchie[x][i]);
}
void solve()
{
    for(int i=1; i<=n; i++)
        if(viz[i]==0)
            {
                dfs(i);
                ++nrcomp;
            }
    g<<nrcomp;
}
int main()
{
    read();
    solve();
    return 0;
}