#include <fstream>
#include <vector>

#define NMAX 100005

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

int n, m;
int x, y;
vector<int> mat[NMAX];
int f[NMAX];
int counter;
int i;

void dfs(int);

int main()
{
    fin >>n>>m;
    for (i = 1; i <= m; ++i)
    {
        fin >>x>>y;
        mat[x].push_back(y);
        mat[y].push_back(x);
    }

    for (i = 1; i <= n; ++i)
        if (!f[i])
        {
            counter ++;
            dfs(i);
        }

    fout <<counter<<'\n';
    fout.close();
    return 0;
}

void dfs(int nod)
{
    vector<int>::iterator it;
    f[nod] = 1;
    for (it = mat[nod].begin(); it != mat[nod].end(); ++it)
        if (!f[*it])
            dfs(*it);
}