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

#define N 100100
#define pb push_back

vector <int> a[N];
int n,i,x,y,m,c[N],nr;

void conex (int k){
    c[k] = nr;
    for (int i = 0; i < a[k].size (); ++i)
        if (!c[ a[k][i] ])
            conex (a[k][i]);
}

int main()
{
    ifstream fin ("dfs.in");
    ofstream fout ("dfs.out");
    fin >> n >> m;
    for (i = 0; i < m; ++i){
        fin >> x >> y;
        a[x].pb (y);
        a[y].pb (x);
    }
    for (i = 1; i <= n; ++i)
        if (!c[i]){
                ++nr;
                conex (i);
            }
    fout << nr;
    return 0;
}