#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, nc, m, i, j, x, y;
vector <vector <int>> v;
vector <int> s;
void dfs (int vf)
{
    s[vf] = 1;
    for (int i = 0; i < v[vf].size(); i++)
    {
        if (s[v[vf][i]] == 0)
            dfs(v[vf][i]);
    }
}
int main()
{
    fin >> n >> m;
    v.resize(n+1); s.resize(n+1);
    for (i = 1; i <= m; i++)
    {
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i = 1; i <= n; i++)
    {
        if (s[i] == 0)
        {
            dfs(i);
            nc++;
        }
    }
    fout << nc;
    return 0;
}