#include <fstream>
#include <vector>
#define NMAX 100010
#define pb push_back

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

int n, m, cc;
vector <int> v[NMAX];
bool viz[NMAX];

void DFS(int nod)
{
    viz[nod] = 1;
    for(int i = 0; i < v[nod].size(); ++i)
        if(!viz[v[nod][i]])
            DFS(v[nod][i]);
}
int main()
{
    f >> n >> m;
    for(int i = 1; i <= m; ++i)
    {
        int x,y;
        f >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }
    for(int i = 1; i <= n; ++i)
        if(!viz[i])
            DFS(i), cc++;
    g << cc;
    f.close();
    g.close();
    return 0;
}