#include <fstream>
#include <vector>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector < vector <int> > v;
vector <bool> viz;
void dfs(int node)
{
    viz[node] = 1;
    for(auto i : v[node])
    {
        if(!viz[i])
            dfs(i);
    }
}
int main()
{
    int n, m, i, a, b, cnt = 0;
    fin >> n >> m;
    v.resize(n);
    viz.resize(n);
    for(i = 0; i < m; i++)
    {
        fin >> a >> b;
        a--;
        b--;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(i = 0; i < n; i++)
    {
        if(!viz[i])
        {
            dfs(i);
            cnt++;
        }
    }
    fout << cnt;
    return 0;
}